I have one in .22 and its great although you only get about 50 shots off a charge. Up where I am there are loads of Rabbits so you need a bottle in the truck all the time.
The Ultra is realy small and great for shooting out of the truck.
The mags can be a bit iffy but BSA will change them no probs if you get a bad one.
I would give it 8 out of 10.
Andy.