Actually, I had very high hope for it going in. I already knew that it fixed most of the things that I didn't like about BW, which are that it was too linear, too story driven, and not enough post game content. And I knew that there are a lot of legendaries available in the post game, so I was excited to catch them so that I could bring them forward to Pokemon Y when Pokemon Bank came out. In the end it exceeded my expectations.
I think I liked it more than Y because honestly, I don't think Y was all that good. It was a great experience on my first playthrough simply for the novelty of playing Pokemon in 3D, but once that wore off the game felt kinda boring. I'm hoping Z will be better in the same way BW 2 was an improvement over BW.