Other than the very confusing exclusion of the battle frontier from emerald, and the overall low difficulty, i will say, this is one of my favorite pokemon games. In general, the game i've sunk the most hours into. I'm still not fully over losing my copy on a trip a few years back, that is one of the most unfortunate things to have happened to me.
I love hoenn, i love hoenn pokemon, i love the characters, i love this game. Also, because it's gen 6, it is the peak of pokemon online connectivity. The PSS has yet to be topped in terms of accesibility and usefulness.
The delta episode is fine, a compromise for not remaking emerald instead, but then why not just add the battle frontier???