Finally I managed to squeeze default factory install of Windows XP Tablet PC Edition to my 16GB Transcend 300x. It was partitioned as 8GB FAT32 + 8GB unpartitioned, because I plan to use the boot partition with EWF and the rest was for EWF config and almost 8GB writable space would be for persistent files, Documents and Settings etc. The IBM/Lenovo installer was getting on my nerves as it threw bunches of errors at me, but despite that, after numerous reboots, the system was up and running. It was completely repartitioned (10.7GB + 4.5GB ibm_service). In last step, my big partition was converted to NTFS without asking. After experiencing the 10s boot of clean XP install, I was quite disapointed and started removing bloat. Apps first of all, symantec client security starts and runs about 5 services!! From Run and Startup I removed unnecessary things, turned off APS. Now the system takes 17s to boot into logon screen and another 12s to desktop. There is much playing with left, i expect another boost especially with the EWF. What annoys me is that the cursor stuttering problem is still here. It is a property of the factory install. I had task manager open and tried to identify processes that could cause it and suspicious are rundll32.exe (thanks Bill, that helped, really

) and 1XConfig.exe. I'll investigate further.
To sum it up, I recommend CF upgrade wery much, especially non tablet owners, because they are much less dependent on the lenovo install. The system is very responsive, silent there are no clicking pauses in HDD operation. For me, this upgrade was very expensive:
Transcend 300x..... 3500CZK
USB DVDRW..... 2000CZK
Addonics 2xCF>IDE......1000CZK (big to thanks to my friend from hungary)
USB IDE converter .....250CZK
which totals to 6750CZK =~ 280 euro for 16B SSD. But there is lot of useful byproducts

+uncounted media spoiled by lenovo "create recovery media"
Careful with cf insertion, when badly inserted, thinkpad may not react to power on button and it may continue to do so fooling you into thinkin it is dead. When I unplugged the battery and connected the pwr cord only for power up trial, it behaved much better.
Proudly changing the signature now
EDIT: power measurements using mobile meter show 12-13w in use with wifi, maximum battery life profile and max brightness which is definitely less than with hdd. When the display turns off, the consumption drops to 8.8w, so the display eats 4W on max brightness, I found that interesting.