Congratulations on your new purchase! I do not have information on what changes have taken place between the 2014 (my model year) and the 2015. What I can tell you is that we LOVE this camper! The features are beautiful, there's lots of space for sleeping and storage and just walking around. It's pretty impressive for it's length. We have had no major problems with it whatsoever!
A couple of improvements that I wish they would make would be:
1. The a/c vent that's in the bathroom should really be further out into the living area where it could point into the bunks and into the bathroom. It gets hot in those bunks!
2. The faucet in the bathroom is puny and hardly comes out over the sink. Just a longer faucet head would be fine - nothing fancy.
OK seriously...that's about all I can think of right now for major improvements...and they're really pretty minor. It's a great trailer. Enjoy it!