I wouldn't suggest this regulator to anyone that's going to run an e- grip on their gun. This regulator has a real crappy recharge rate. I must of had my e-grip set at about 10 bps and the regulator was set at 375 psi and it zeroed out on me. Plus, like I said, the recharge rate is horrible. It drops too much when you shoot. Plus mine developed a leak after just testing out twice. I've heard two other people tell me that theirs started leaking after a few uses. I got mine for $37 new, so I'm thinking the guy didn't care what he could get for it, he just wanted to get rid of it. That's my take on it at least. However, if you're not using an e-grip then I guess it would be a decent reg for your stock gun.
Buy it if you have a stock grip and plan on staying like that for a while, but toss it as soon as you upgrade to an e-grip