I rarely dislike Pokémon music, but X&Y's Gym and Elite Four themes are severely lacking in terms of variety, they were mind-numbingly repetitive
Plus, the E4 theme takes so long to build up to its climax that I'm usually 3/4 through their team by the time it peaks
DPPt's themes are very MIDI-friendly, especially the Lake theme and Eterna Forest
Spoiler:
I put them into Synthesia, and apart from Synthesia's hilarious percussion choices (I'm pretty sure there's no police whistles or barking in the games...), they sound the same
Well, the music is a big part of pokemon for me! But everyone has their own opinion.