Just got a new 2018 Pro, upgrading from a 2013 Air. At the store yesterday they first sent me home with a 2017 accidentally.
I don't have a ton of experience with the 2017 keyboard other than the brief time I had it at home before returning it and testing it out in the store.
That said, I do feel like there's a definite difference in feel between the 2017 and 2018. The new one feels less metallic, if that makes sense. As a lover of mechanical keyboards, I was really concerned about not liking this keyboard, but so far I'm pleased.