Installed Arch and xmonad. Learned how to use xmonad.
I love it now, and I might just continue buying used X220s for the rest of my life or until I'm unable to source decent batteries for them.
12.5" screen is pretty small for most people. Having a low resolution doesn't help.
Only some models (the ones that came with an i7 processor, I think) have USB 3 ports, and even those models just have one.
It doesn't have an HDMI port. It's thick and heavy. They have 2nd gen core series Intel processors which are way, way less power efficient than the 4th gen or newer processors.
It's also got slow wifi and it has a wifi card whitelist in the bios, so you can't put a better card in it.
Pretty much the only reason to buy one nowadays is if you need something really cheap that runs linux well, which is exactly why I bought one in 2015 when I was a senior in college and also the reason I stopped using it as soon as I could afford something better.
I have one as my backup Windows laptop, but I couldn't use it every day.
Fortunately it is extremely easy to swap screens on the X220, and the IPS screens are cheap on eBay.
You are dead on about the resolution, though. That's the reason I stopped using my x220.