I've got ASV's. (Motomummy should have them for $200 after adding them to your cart).
The unbreakable guarantee is nice, but other than that, the only other difference is that they have more adjustability (is that a word?) than Pazzo's. The pazzo levers have a set amount of positions, ASV's have an adjustable mechanism that gives you damn near endless adjustability.
But keep in mind before you drop the money, that unless you have completely abnormal hands, after market levers are nothing more than an aesthetic mod.