There are a few threads on here about Asus. The most positive one I can remember was OcUK stating they used to be really crap, but now they're only a bit crap. A couple of reps came on here for a while, promised things like a 5 day turnaround that simply didn't happen.
I had very little fun when an Asus board failed, the initial turnaround estimate was 12 weeks. OcUK sorted that out on my behalf (posted me a Gigabyte board), I've no idea if they bothered to chase Asus or if they wrote it off.
I, personally and slightly irrationally, won't buy from Asus again. Lovely motherboards, made by a company that just doesn't give a damn about individual end users.