The 350w is probably Airwatts, this is the true way to measure how good a machine is.
The normal way they get quoted like 1500w is just the amount of electricity it uses, doesn't mean it picks up any better than a 1000w unit.
Dyson always quote Airwatts, dont think alot of other makers do, of course it may be how much electric the oreck uses, does not mean its a bad machine depends on how many Airwats it is.