Well, as an owner of a Vax 121 and then a Powa model, I can't say their suction is bad.
Infact, in my opinion I think they were probably the best British gadget Vax ever made. The quality slipped however when they moved production sadly, and of all places in the world, which must have been a smack in the face for British buyers, Vax set up home for sales of all of their tubs in Australia. The tub could have stayed here and progressed - when you look at Karcher and other budget rivals who are still selling 2 in 1 or 3 in 1 machines - there's clearly a market for them, even if most are bulky and heavy.