In the average home, an upright may not be the best choice. They are great on wall to wall carpeting, but simply are too bulky to fit into tight spaces. And even if you have carpeting, NO vacuum will truly get the far edges of each carpet, and over time, you will see a grayish line forming along each wall. This is just dust which has settled in. When THAT happens, its time to call a professional carpet cleaner.
I would guess that for a cleaning company, having several types of vacuums would be of help. Upright AND wand. See, the wand types offer a lot more attachments, to help with specific jobs, where most uprights dont have this at all. Some of Sharks uprights do have attachments, but they STILL cannot get into really small spaces, like between furniture. I own all these types, and some jobs require one, others another. That is just the way it is, because I care about doing things well.