Many years ago my father-in-law gave us a commercial vacuum (Windsor Sensor) that's typically used in hotels and hospitals. The thing's built like a tank and is easily serviced. It's a good choice if you don't mind a heavy vacuum, and it's only incrementally more expensive than a Dyson.
We looked at what the staff were using a couple of hotels and bought the ORECK XL COMMERCIAL. It is a simple vacuum with bags so it’s easy to clean. No extra features to break. The price was much cheaper than any Dyson vacuum. It’s been dead reliable for over 10 years and seems like it will just keep running.