Brian, linear tracking arms that are of the kind of quality that you would need, are all air bearing types. They have alot of issues with leveling, keeping moisture out of the lines, and the noisy air pump, which usually has to be kept in another room, with the air lines running through the house to get to the pump. They have their strong points, but they are often times more of a pain in the ass than they are worth. If you want to play with pressure valves and gauges, and air lines and pumps, and moisture traps, and level the table every time you play, or risk breaking off your cantilever, then go for it. When they are right, a really good linear tracker can do the job as good as it can be done. They require constant attention.
There is a Moerch that is a dual-pivot. That's what I thought you were referring to. I still think the OL is better.
There is a Moerch that is a dual-pivot. That's what I thought you were referring to. I still think the OL is better.

