I am thus far HUGELY happy with mine. I bought the one they recently came out with...dual stage. I did have to find a washer locally, as the one they sent with it really wasn't the right size, but that was an easy task at a local welding supply place. They gave me 5 at no charge, just because they're nice and don't generally have much call for this specific washer.
My regulator has been set-it-and-forget-it. Not even the slightest fluctuation showing in either tank pressure or working pressure. I'm still tinkering with the needle valve and determining rate. That's an issue of what appears to be unreliable drop-checker solution (I'm going to try Fluval's highly rated stuff to see if it's any better. Not really sure the stuff from Co2Art is any good. It goes to yellow fast and then stays there, even overnight with no Co2 flowing).
Deep Blue Professional 50g
Current USA Satellite+ Pro LEDs (24 & 36")
Fluval 406 filter
CO2Art Advance Professional Aquarium CO2 Dual Stage
Hydor Koralia Circ Pump - 425gph x2
DBP 20g long - low tech