In most instances Treemagineers inspired hardware works best with other DMM products. When Treemagineers gear is paired with other brands they don't seem to work as well. eg the Ultra O with the Hitch Climber is a perfect combination but when you combine the Petzl OK (supposedly oval) carabiner with Hitch Climber it's a dismal failure.
But… here's one for the books - a Petzl product that possibly works better than the DMM original.
The hard nylon Ultralegere has a convenient groove milled around the center hole of the sheave which sits perfectly on the rounded top cheeks of the Pinto Rig, allowing it to clip snugly into place.
The Ultralegere pulley sheave itself is almost too large for the Pinto Rig but there is still enough room for a small parrell ball to pass through for retrieval. Yes, it's ugly but it works.
A positive feature of this product combination is the size of the center hole which happens to correspond with the holes on the Pinto. The hole diameter is designed to accommodate a carabiner bar or climbing line.
Climbers have a couple of niggles with the official Pinto Rig Spacer. Most complain the center hole is too small to accommodate climbing lines (the current version of the spacer only accepts cord up to about 9mm - effectively friction cords only).
Another issue, which is presumably a design feature, is the 'floating' nature of the official spacer. That is, the spacer does not fit snugly between the two side cheeks - instead, it 'floats' back an forth along the rope between the two cheeks - nothing major, just annoying.
The fact you have to buy the Pinto Rig Spacer over and above the Pinto Rig itself also makes this a grudge purchase. Treetools plan to combine the two - Rig and Rig Spacer - at a favorable price to get around this problem.