I bought the PV12 from
Prochem to "check it out". I love it, works great, has an automatic height adjustor from different types of rugs to floors. The upholstery tool is "live", meaning you just pull it out and it is working, you don't have to plug the other end into a hole on the top of the vacuum. That is a big time/saver as well as the fact the upholstery tool works much better (no air leaks).
The Prochem is a little on the expensive side, but they last for a long time. Another plus is that your local Prochem distributor can order your bags/parts pretty easily, so don't have to make two stops?
We use a Sanitaire here for the showroom, and it works awesome too but it's just a little heavy.
Hope my $.02 helps!!