I am. I was using a Trace Elliot AH1000-12, but got sick of lugging it around (I like everything in one rack) so I picked up a pre-amp and started using it with my old QSC 2450, but the QSC is a tank and a half, and was way more amp than I needed anyways, so now I'm using a Crown xti1000 (that I bought here on TB- Thanks swpyne). For most clubs I just use one Tour 410, but for outside shows I use a pair of them.
To answer your first question; I like them a lot. They sound great (IMO), and they're extremely light. Haven't had a problem yet and I've been abusing them for a couple of years now.
As far as how hard do I push them: the answer depends on where we're playing. Most shows I don't have to push them very hard at all. Other shows (I'm ashamed to admit) I've downright abused them.
Great sounding, reliable cabinet for a good price. IMO, you can't go wrong.