Rafferty
If you're talking about " tub " vacs, look at the Yes vac, from Denis Rawlins, it,s more expensive, but has water filtration, gives 100% suction all of the time, unlike Dyson, who claim this
You can also add aromatherapy oil to the water, which circulates while cleaning and it has a spcially commissioned " cool running" motor allowing long periods of use without overheating..............
No, I'm not on commission, just passing on information.
For carpets, you can't compete with a good upright and you will have to try them out, but one of the most important things, is to empty it often enough and clear the brushes daily.