I'm a lifelong Diablo fan, so I'll probably pick this up next week. One thing that bugs me is that folks keeps saying "it's just cosmetics". To me, this ignores the fact that, since Diablo 3, your character's look is part of the fun. That cool armor you just found looks cool too. Now I worry that the gear is going to look boring so that you're subtly nudged in the direction of buying cosmetics.
Basically, I still want to be able to play dress-up.