We have the G Tech ones, both the upright and the hand one. They are absolutely brilliant. They pick up cat hairs plus all the usual dust etc no problem. When you switch them on there's no effort to push them around as they seem to go by themselves. We took our other vacuum cleaner to the dump recently as we won't use it again.
I would highly recommend these vacs. (I don't work for the company, I just clean my own house!)
BBC Radio 4Extra Scheduling Shake-Up.