I haven't owned one but I've driven several cars with them on some long haul rides, If I were building an OD automatic car I wouldn't go any other way than the Gear Vendor unit, they take MAJOR abuse and are a dream to cruise at highway speeds even with a fairly deep rear gear.
For an OD manual trans and a 100% bolt in setup, there's no other choice than the new Passon 5 speed (see pic), they are a BEAUTIFUL piece of workmanship!