report after few months...
I think, I found reason why T9900 i W500 is like holly grall
this config is very rare because he have few problems..
first, I have new MB with bios 7V (newest hardware)
ok, some about problems
firs is heat!
its possible to overheat only by torture T9900 (yes, I use best diamond paste and I do many test)
CPU can reach almost 100stC with tpffancontrol with settings on full fan speed (over 4500 rpm not avail in normal bios)
second is PWM!
when I run together test GPU and CPU PWM on MB reach very high temp and bios slow down cpu at half (1,5+GHz)
testing under OCCT software
in some games (Life for speed) I notice this situation
third is most funny

when switch setting in bios in thermal managment from "maximum" to "balance" in AC scheme windows don't start, becouse T9900 reach very high temp under bios settings. When W7x64 starts W500 just crash becouse cooling is too weak! - for start iI use vacum cleaner

(cpu temp 38C)
I do not notice this problems with T9600
Do I back? I don't think so. Its hard to believe, but T9900 is very powerful, system works great and its strange, but I feel difference.
I very recommend do some trick under system recovery

when first step under recovery is done (after coping fom cd to HDD), I just swap under other system all old software and drivers to most latest but not power manager and active connections
(3.67 and 5.98)
my config under recovery (swapped files)
Bluetooth with Enhanced Data Rate Software II Ver. 6.2.1.31
Conexant Audio Software Ver. 4.92.12.0
ICH9 4k512e - YES! its ahci rapid driver version 9.6.4.102 (for advanced sector 4k - req for new disk with advanced format) ps.2 remove turbo memory!
Integrated Camerave. Ver. 1.32.500.0
Intel Wireless LAN (11bgn) Ver. 13.04.0000
Lenovo Fingerprint Software for Windows 7 (64-bit) Ver. 3.3.2.50
Ricoh Multi Card Reader Driver Ver. 3.64.02
Synaptics ThinkPad UltraNav Driver Ver. 16.2.19.14
ThinkPad Switchable Graphics Driver Ver. 8.792.5.2-120504a-138564C
ThinkVantage GPS Ver. 2.81
WAN Ericsson F3507 Ver. 6.3.3.6
Power Manager Driver Ver. 1.65.05.20
and software
Access Connections Ver. 5.98
Client Security Solution 8.30.0057.00
EasyEject Utility Ver. 2.39 added under revovery by ctrl+alt+del and task manager
Hotkey Features Integration Ver. 3.87.0000
Power Manager utility Ver. 3.67
Hotkey Features Integration Ver. 3.89.0100
Lenovo Mobile Broadband Activation 4.8.0003
ThinkVantage Communications Utility Ver. 2.11.0.0 added under revovery by ctrl+alt+del and task manager
Hotkey Features Integration Ver. 3.89.0000
after this I put intel turbo memory and manully install driver thru device manager (its very important!, you cant run setp becuse this swap ahci driver)
then I configure ITM as temp
no more temp files on main disk!
I use ITM as temp for browsers, system,etc
after this, SP1 (lenovo OEM W7 recovery don't have version with sp1)
and updates without bellow spy and another crap
wusa.exe /uninstall /kb:971033 | REM;update for windows activation technologies
wusa.exe /uninstall /kb:2505438 | REM;Although it claims to fix performance issues, it often breaks fonts
wusa.exe /uninstall /kb:2670838 | REM;The EVIL Update, breaks AERO on Windows 7 and makes some fonts on websites fuzzy, Windows 7 specific update only, do not install IE10 or 11 otherwise it will be bundled with them, IE9 is the max version you should install
wusa.exe /uninstall /kb:2882822 | REM;update for adding itracerelogger interface support
wusa.exe /uninstall /kb:2902907 | REM;description not available, update was pulled by microsoft
wusa.exe /uninstall /kb:2922324 | REM;description not available, update was pulled by microsoft
wusa.exe /uninstall /kb:2952664 | REM;update for upgrading windows 7
wusa.exe /uninstall /kb:2976978 | REM;update for windows 8.1 and windows 8
wusa.exe /uninstall /kb:2977759 | REM;update for windows 7 rtm
wusa.exe /uninstall /kb:2990214 | REM;update that enables you to upgrade from windows 7 to a later version of windows
wusa.exe /uninstall /kb:3012973 | REM;upgrade to windows 10
wusa.exe /uninstall /kb:3014460 | REM;update for windows insider preview / upgrade to windows 10
wusa.exe /uninstall /kb:3015249 | REM;update that adds telemetry points to consent.exe in Windows 8.1 and Windows 7
wusa.exe /uninstall /kb:3021917 | REM;update for windows 7 sp1 for performance improvements
wusa.exe /uninstall /kb:3022345 | REM;update for customer experience and diagnostic telemetry
wusa.exe /uninstall /kb:3035583 | REM;update installs get windows 10 app in windows 8.1 and windows 7 sp1
wusa.exe /uninstall /kb:3042058 | REM;update for cipher suite priority order (contains winlogon spying elements)
wusa.exe /uninstall /kb:3044374 | REM;update that enables you to upgrade from windows 8.1 to windows 10
wusa.exe /uninstall /kb:3046480 | REM;update for migrating .net when upgrading to later version of windows
wusa.exe /uninstall /kb:3050267 | REM;Windows 10 upgrade preparation but also adds the option in GPEDIT to disable Windows 10 upgrade altogether so you may want to actually install this
wusa.exe /uninstall /kb:3058168 | REM;activate windows 10 from windows 8 or windows 8.1, and windows server 2012 or windows server 2012 r2 kms hosts
wusa.exe /uninstall /kb:3064683 | REM;update for windows 8.1 oobe modifications to reserve windows 10
wusa.exe /uninstall /kb:3065987 | REM;update for windows update client for windows 7 and windows server 2008 r2 july 2015
wusa.exe /uninstall /kb:3065988 | REM;update for windows update client for windows 8.1 and windows server 2012 r2 july 2015
wusa.exe /uninstall /kb:3068708 | REM;update for customer experience and diagnostic telemetry
wusa.exe /uninstall /kb:3072318 | REM;update for windows 8.1 oobe modifications to reserve windows 10
wusa.exe /uninstall /kb:3074677 | REM;compatibility update for upgrading to windows 10
wusa.exe /uninstall /kb:3075249 | REM;update that adds telemetry points to consent.exe in windows 8.1 and windows 7
wusa.exe /uninstall /kb:3075851 | REM;update for windows update client for windows 7 and windows server 2008 r2 august 2015
wusa.exe /uninstall /kb:3075853 | REM;update for windows update client for windows 8.1 and windows server 2012 r2 august 2015
wusa.exe /uninstall /kb:3080149 | REM;update for customer experience and diagnostic telemetry
wusa.exe /uninstall /kb:3081437 | REM;august 18, 2015, compatibility update for upgrading to windows 10
wusa.exe /uninstall /kb:3081454 | REM;september 8, 2015, compatibility update for upgrading to windows 10
wusa.exe /uninstall /kb:3081954 | REM;update for work folders improvements in windows 7 sp1 (contains telemetry elements)
wusa.exe /uninstall /kb:3083324 | REM;update for windows update client for windows 7 and windows server 2008 r2 september 2015
wusa.exe /uninstall /kb:3083325 | REM;update for windows update client for windows 8.1 and windows server 2012 r2 september 2015
wusa.exe /uninstall /kb:3083710 | REM;update for windows update client for windows 7 and windows server 2008 r2 october 2015
wusa.exe /uninstall /kb:3083711 | REM;update for windows update client for windows 8.1 and windows server 2012 r2 october 2015
wusa.exe /uninstall /kb:3086255 | REM;september 8, 2015, security update for the graphics component in windows (breaks safedisc)
wusa.exe /uninstall /kb:3088195 | REM;october 13, 2015, security update for windows kernel (reported to contain a keylogger)
wusa.exe /uninstall /kb:3090045 | REM;windows update for reserved devices in windows 8.1 or windows 7 sp1 (windows 10 upgrade elements)
wusa.exe /uninstall /kb:3093983 | REM;security update for internet explorer: october 13, 2015 (ie spying elements)
wusa.exe /uninstall /kb:3102810 | REM;windows 10 upgrade elements
wusa.exe /uninstall /kb:3102812 | REM;windows 10 upgrade elements
wusa.exe /uninstall /kb:3107998 | REM;Removes Lenovo USB Blocker
wusa.exe /uninstall /kb:3112336 | REM;update for windows update client for windows 8.1 and windows server 2012 r2 december 2015
wusa.exe /uninstall /kb:3112343 | REM;update for windows update client for windows 7 and windows server 2008 r2 december 2015
wusa.exe /uninstall /kb:3123862 | REM;updated capabilities to upgrade windows 8.1 and windows 7
wusa.exe /uninstall /kb:3135445 | REM;windows update client for windows 7 and windows server 2008 r2: february 2016
wusa.exe /uninstall /kb:3135449 | REM;windows update client for windows 8.1 and windows server 2012 r2: february 2016
wusa.exe /uninstall /kb:3138612 | REM;windows update client for windows 7 and windows server 2008 r2: march 2016
wusa.exe /uninstall /kb:3138615 | REM;windows update client for windows 8.1 and windows server 2012 r2: march 2016
wusa.exe /uninstall /kb:3139923 | REM;
wusa.exe /uninstall /kb:3139929 | REM;security update for internet explorer: march 8, 2016
wusa.exe /uninstall /kb:3146449 | REM;updated internet explorer 11 capabilities to upgrade windows 8.1 and windows 7
wusa.exe /uninstall /kb:3150513 | REM;may 2016 compatibility update for windows
wusa.exe /uninstall /kb:3163589 | REM;
wusa.exe /uninstall /kb:3173040 | REM;
after this, run clean disk for clean old files from windows update
run disk defrag
and viola!
super stable, fast exclellenty working system based on Windows 7x64
no one more lenovo updates requried, no one old drivers and other trash
I do this same on X120e, X301, W700 and yes! old T43p
Recovery from W500 Win 7 x86 generally fit for T43p

some drivers must be add manually, but this is not problem.
my Old IBM 14" T43p 2,26GHz plus 2GB RAM, plus hitachi 7k100 100GB works fine with Windows 7 x86 pro as service computer in garage
cheers!