It's good but definitely flawed, and it's just lazy of Sakurai and Nintendo to not keep supporting balance. I mean, I guess I can see why not- they've already raked in all the cash, at this point all they'll have to bother doing is keep the game working. Yet another reason for me to dislike Sakurai, but I can't imagine it's his decision alone.
EDIT: Just to be clear, I think it's fine that he isn't going to maintain custom movesets. By nature some of them are a bit messy and don't even work online, but the default movesets at least need to be patched. If he think it will 'never be the end of it' well... I thought that's what Bandai Namco, a team that actually knows about fighting games, is there for?