I use Hayes both end on mine. I've got XT shimano's on my dh bike though and they're ace.
Every pair of hope I've had have gone wrong, without fail. Avids are pretty cool but I've found getting parts can be a real pain. If you're willing to put the effort in with maintenance then Hope would do the job. I just like to pick up a bike, ride it, then throw it back in the garage though so thats maybe why they didn't work for me.
Could I BE any more vague