The Hero is clocked at over 500MHz. G1 and Magic are both rated at 384, not the Hero.
Still not as fast as the 3GS but thats not due to the slower CPU. Its OS just isn't optimized to take advantage of the speed. I'd be tempted if it wasn't for the serious lag. And when you open more apps, more lag. I do like the interface though and am kind of indifferent to the chin.