I've been using a T420. Would I gain much by moving to an X220/X230 ? I've heard they are slightly more performant, but I'm not sure how going from a 14' to a

I've been using a T420. Would I gain much by moving to an X220/X230 ? I've heard they are slightly more performant, but I'm not sure how going from a 14' to a 12.5' screen will feel.