Paul,
Interesting to note about vacuum cleaners,
that most of the losses involved in a cleaner is caused by the air path through it.
Therefore, if you took out the bag and the air filters, you'd have somewhat more suction.
Sure the motor probably wouldn't last too long and you'd have to be Hercules to move the head over the floor, but the cleaner would be more efficient.
One appliance that has seemingly escaped being turbo-charged, is the humble toaster,
I've got a relatively new one here and it's only rated at 300W, it can blacken toast like you wouldn't believe though!. [Linked Image]