Pros
>Really solid Pokemon designs with only a few exceptions
>Great human character designs, the NPCs in particular
>Excellent music
>Mega gimmick remains the best gimmick to date
Cons
>Atrocious and disjointed region
>Extremely stupid story
>Many characters with wasted potential or simply do nothing
>bad trends like gen1 pandering and humanoid/jobmon starters started here
Mixed
>Transition to 3D was rough, overworld is rather ugly but battles look good (for the time)
When all is said and done I look back on gen 6 as the single most flavorless and bland gen to date. I don't think it was bad but it needed a "third version" sorely in order to really stand out. It doesn't help that gen 7 mogged it in almost every way and I don't even like gen 7 very much.