Replace beloved X61T... Suggestions?

[bobcardone]

Well, the time is approaching to retire my trusty X61 tablet.
It's been my daily driver for over 5 years at university, and besides poor battery life was just about everything I wanted in an ultraportable.

I'm the designated IT guy in my circle of friends and family, all of which have ThinkPads (go figure...)
At one time I had 7 X61 tablets deployed amongst them, eventually migrating them to newer and bigger ThinkPads.

I have newer and faster machines at my disposal, but I always grab my X61T.
It's a unique build... X60T outer shell (with the colored IBM logos on the lid and palmrest) with a X61T L7700 planar, MultiView/MultiTouch, 8Gb ram and 80g SSD.
A keeper, but soon to be retired... almost a decade old!

My quest is a replacement that keeps the best features of the X61T but with newer hardware.
Requirements:
12" convertible tablet/laptop format
i3/i5/i7 CPU 2nd gen or newer
Classic keyboard
MultiView/MultiTouch
IPS screen
ThinkPad (Duh...) I also have a Panasonic ToughBook CF19, but it is more of a weapon than a laptop.

I really don't need a lot of grunt in the GPU and CPU department, battery life is more important to me than horsepower.
Standard resolution is OK, I don't want FHD. Just a bright IPS.

Conventional thinking suggests X220T or X220Ti.
I'll be using a mSATA SSD drive and will max out memory.
Battery life is important. The X220Ti has an i3 CPU whereas the X220T only came with i5 and i7.
How crippled is the X220Ti, and could one mix and match components to get a "perfect" balance, as I did with my trusty X61T?

Any comments, thoughts or "out of the box" ideas would be greatly appreciated!

[TPFanatic]

With the classic keyboard mod I imagine you would also have the X230T to consider in the swiveling tablet convertible segment. What sort of advantages does Ivy Bridge have over Sandy? Higher CPU clocks, better graphical performance and supposedly battery life?