Yes, I have. See this thread.
http://www.horizonsunlimited.com/hub...nd-racks-39201
They are good. The fit isn't perfect, and as a result one bracket snapped and had to be welded. They carried a lot of weight, probably too much, but eventually failed and the pannier rails broke, but to be fair this must have been at least partly due to the rear sub-frame breaking first and putting undue loading on the rails.
It's rated for max 10kg in each pannier. I think if you stuck to that and the frame of your bike doesn't snap, they would be good enough for moderately adventurous riding in places like Mongolia. Ride a bit more aggressively and they'd break sooner. I took things pretty easy, mostly.
I did also crash in Mongolia and ripped a box right off, which can't have helped.
I was a little unimpressed with one of the welds on one rail, but it didn't fail there. The mounting hardware is good quality and up to the job, and didn't require much re-tightening on the road.
I'd say it all depends on where you're going and how hard you ride. Anywhere rough if you ride hard, I'd say no, unless you're really careful with weight.
I found I had to use half a dozen bungies across the boxes to hold it tight across the top, without which the boxes on each side sag and bounce around more, stressing the rails.
I think the H&B is as going to be as good as any other (I couldn't find any other), and there are inherent limitations on where and how you can mount the rails. The rear rack is fine, but the fit is a little tight. The rails mount to the only places they can on an XT, which includes the rear indicator mounts. They're not all that robust, which worried me, but again, that's not where it broke.
I'm also thinking very hard about whether to use them in future, and thinking of going with soft-bags, but there are other threads about that.
Al