I don't own a "pv" so I don't know if
Prochem offers the different models that vac is made in, but I do own about 40 Windsor Sensors which are the same vacuum. They are very reliable and very repairable.
With Windsor there are a few variations in each size they produce. There used to be 2 models with and auto adjusting brush height, the Sensor and the Sensor XP. The XP seems to have a more aggressive pre-programmed brush setting and maybe a little more suction. Later they changed to a manual adjusting brush height model, and the XP retained the auto adjust.
For some reason the Auto-adjusting vacuums are not all created equal. Some of them seem to have different brush pressure settings that can't be adjusted (to my knowledge). Additionally some seem to have different "bag full" settings, some will fill a bag much more than others before they require bag replacement.
My favorite is the 18" xp model for commercial and the 12" xp for residential, then the manual adjuster, then the non xp auto adjuster. I would assume if your buying it new and it has an auto adjusting feature it's probably the Windsor equivalent of the xp.