Don't own one, but have played with them and for the money its a great gun. The only bad thing about them is the feedneck and ASA, but those are easily replaced with a clamping feedneck and on/off. Also the trigger felt a bit wobbly sideways, but it didnt affect performance and you always can replace it with a upgrade trigger if it bothers you.
Before i played with an ion, i regarded them als low-end cheap ass plastic electro guns. But after playing with one i realize they perform pretty darn good compared to other cheap electro's.