I'll admit, there are things I don't like about Gen 5. I don't like Unova from B/W 1, and by that I mean the structure of the map, it's like after making more or less elaborate maps for the previous games, they completely gave up for B/W. I also miss the mandatory use of HMs to reach new locations (IMO it gave the game a Zelda-esque feel) , replaced by a purely story-driven progression which to me feels like constant hand-holding.
On the other hand, I like the graphical enhancements, especially the very fast battle animations and some spectacular locations like the Skyarrow Bridge. I like the seasons system, changing music (when you talk to musicians on the street) and all those little details that make the game's world come to life. While I don't like the overall Unova map, I do like the new approach when it comes to designing the levels themselves, where you rarely go in high grass if you don't choose to. I thank GF for finally making the inventory unlimited, and, in B2/W2, allowing to immediately use a new repel when the old one wears off (I use them a lot, so to me it's a significant improvement) . I like not being subjected to "push the block" puzzles or having to run after roaming Pokémon anymore.
Every generation brought new things and took some old things away. Pokémon evolves with every new generation, just like all the other series do. In this generation in particular, GF took a different approach and changed some of the game's formula. While some of the changes were hit-or-miss IMO, I do hope that GF will keep changing the formula in the future. Personally, I thought Gen 4 felt too similar to Gen 3, and I thought it made those games look less like new games, and more like rehashes of Gen 3. I had no such feeling while playing Gen 5, and that's what I want from future games.