My mate had one problem:
it fires that fast he kept breaking paint (only had a revvi) ... though that will be all sorted now he has an Egg2 and he's getting the eye
Really mate, as far as I know he hasn't had any problems at all. I had a go and it was brilliant, light, easy to move around, v fast.
The only thing I found was that you only got about 1000 shots from a 1.5 4500 fill .. so still is abit of a gas hog, but not that bad to be honest, it didn't affect his or my play at all.
Hope this helps