My home button has an inconsistent click and lacks that solid "snap" that my 5S had. It was unnerving at first to my mobile device-related OCD, but not yet worth the trip to a Genius Bar.
On my 6, the home button clicks differently than it did on the 4 or 4. They changed the design a little for the new phones. If it's not giving you problems, I wouldn't worry about it. You could always hit the Genius Bar to make sure.
Every model is a little different. 5s felt different compared to the 5; 6/6+ feels different than the 5S but as stated above, take it to the Apple Store if it feels wrong to you.