So I finally moved. Now I have no room and have been getting rid of most of my collection.
For my apartment managing work, I have only room to keep two uprights. My initial instinct was to hang onto two Sanitaires. But as other folks in my family used them, I realized that Sanitaires take some knowledge and skill to use, which not everyone had. I mean, you do have to pick up the larger bits off the floor (like something as small and harmless as a popcorn kernel, for example), or the Sanitaires will bat them around and spit them out. Also, those small bits can get caught between the belt and brushroll and break the belt. So I had to pick something more user friendly.
I chose a Windsor Versamatic and a Riccar 8925 commercial upright vac. Both are great. But after really using the Riccar, it just felt a bit too heavy and cumbersome. It's a great vac, but it just felt really bulky to push around.
So currently I'm thinking of going all Windsor: a Versamatic and a Versamatic Plus. I know these aren't necessarily the best deep cleaners, but they're solid performers and pretty foolproof to use (aside from being a little heavy to carry around).
I was also toying with keeping a Carpet Pro CPU-1, which like Riccar is a Tacony vac. It's built at a lower price and quality point, but still performs very well with the added benefit that it feels much nimbler than the bulkier Riccar. Here is the link to both: