Would that, perhaps, have been an Eminent Technology ET2? Something like... this?
Reminds me of another tangential arm I was about to get involved with, though with a different persnicketyness. I was about to buy a used Kuzma table with an air-bearing tangential arm on it from a store where I was friends with the manager and he pulled me aside. "I know you. You don't want that. It's beyond your pain-in-the-ass threshold. You gotta put this air compressor in the closet or the noise will bug you and then you run a hose to it and this and that and... I know its cool but... I know you. Walk away."