I have a Scorpion by Dirt Devil. It uses 7 amps (corded, 110V) but is so quick and powerful the time running is short. Normally $50 on Amazon I waited and got one on sale for $30.
I've tried the 12 volts ones, and the rechargeable vacuums. In comparison, the Scorpion is far more powerful. It's not for use with wet, and has a removable filter (no bag)
I love mine.