I have an X201 at work, and REALLY like the build, size, etc., so that for a personal laptop, I am thinking about going a similar route with the newer X220, even with the premium versus a more consumer-oriented option.
But...there is also the T420.
X220 Pro's
Smaller
IPS display (the premium display, according to the datasheet)
T420 Pro's
Larger screen, with 1600x900 resolution
Integrated Optical Drive
Those are the major differences that I am chewing on. The ~$150 premium for the X220 is a secondary difference, and I *think* other differences would not really effect my decision.
But...thoughts or comments on either these items or others that may sway me one way or another?
To begin, I love Thinkpads. I have an X31, X60s, X201s. They are excellent machines for work or school.
I used to use them as my personal machine also.
But don't hate me for suggesting, my new personal use machine is a Macbook Air 11.6" 4GB 128GB, basically fully loaded.
For personal use IMHO you can't beat this thing. It's just so thin, light and believe it or not quite sturdy. It's no carbon fiber/Magnesium alloy Thinkpad, but it's pretty darn good. I've dropped it numerous times, stepped on it etc. Thinkpads stand up to that kind of abuse and so does this machine.
I can't think of a better personal machine for simple browsing and e-mail, minor word processing etc. It is also quite responsive despite what the specs would lead you to believe. The bonus is the low, low cost. I know what those Thinkpads cost. You lose the thinklight/backlighting and the fingerprint reader, other than that it's a great machine. I get 6 hours consistently in battery life, it wakes and sleeps instantly, in sleep it can last 30 days. That kind of instant availability is great to have around the couch. Any time you need to look something up, open it and look it up.
My disappointment with the X220 is that there is no "s" model and 3lbs is step backward from my 2.4lb X201s. The X1 starts at 3.7lbs. To me that's inexcusable when Apple and Samsung can get their 13.3" models to under 3lbs.
I would say think about what you do with a personal machine, if like me, you mostly browse and e-mail this MBA is perfect. If I were a student or I needed a work machine doing a fair amount of Excel or Word or other things I would get a Thinkpad but for a leisure time laptop IMHO there is nothing better than the MBA. Watch for a refresh with rumored Sandy Bridge CPUs coming in a few weeks.
Just throwing that option out there from someone who used to eat, breathe and sleep Thinkpads.
EDIT: I just realized that Thinkpad pricing has dramatically changed recently. At those prices I can see why they are so good. They used to be priced well above Apple/Samsung, but not anymore.