I did use older keyboards like the one on the x220 as well and while the feeling was a little bit better, I just can't use a keyboard without a numpad (reason I am not using 14 or 13 inch laptops) and I also think the keycaps on the newer model are superior
Unless they offer something we can press with decent key travel - and I mean no less than 2.5 mm - I'm not buying.
(For those who don't know what I mean: https://www.pcworld.com/article/557179/full-travel-keyboard-... )