I've nevr "blown through levels like hotcakes." I don't feel power-leveling counts when assessing this because that's not standard practice. It actually takes a fair bit of time to level up if you only do leves and "normal" parties.

Generally in an MMO I like to take it slow on my first character / class, then on the others I'd rather not waste time griding as I've already experienced what it's like for that game. Therefore I think it's good for there to be different options.