As you know all the aftermarket companies use similar products for the engine side of A/C. The difference from what I understand is inside the passenger compartment. The biggest different is how these guys operate the doors on the evaporator unit (read leakage). Most use vaccuum to open/close the cooling doors or ports, as do many OEM cars. Vintage uses electrical motors to open/close these same doors. They say that makes them operate better and I've never heard any others dispute this. I would think the motors would make the units cost a little more. I think the biggest difference with the way these units work would be for the guys that have big cam motors with little vacuum. Most of these companies will sell the bits and pieces like various types of vents by themselves.
