I've got a Tubus Cargo on one bike and a Thorn Expedition on the other. Tubus have a wonderful reputation for reliability, and the Cargo saves 300g over the Thorn Expedition. But I have to say the Thorn is way more stable, and its utterly bombproof construction is possibly worth the extra weight for peace of mind. It's really reasonably priced too, considering the market.
I might actually be on the look out for a new front rack...that Old Man Mountain you mention looks very decent for the weight- though more in the sus-fork/ off-road category, by the looks of it, with only the high rails. I'd prefer to go steel if possible, too.