Well, the MacBook Air keyboard feels a little different from my 13" rMBP. But I have a new 2015 Air and a Late 2013 rMBP (purchased July of 14). So the MBP has more wear on the keyboard. But they don't feel that much different. If anything the Air does have a little more travel, but my MBP feels more precise, and clicker as you've noticed.
I think that's normal, as they are different machines with different thickness and the body is different so it will affect it. I came from a late 2008 13" MacBook that had 6 years worth of keyboard wear on it and it didn't feel that much different after all those years, other than the keys being rather shiny 🙂