I have had that regulator for quite some time now. At one time, it was pulling double duty of providing CO2 to my planted tank and my calcium reactor (both of which required different levels of CO2) and it has never skipped a beat.
Once I set the bubble rate, it stays the same until the entire bottle of CO2 is empty (I have a 20lb bottle.) I operate it at 10psi and this too, does not fluctuate. I run the solenoid on the same timer as my lighting, so it doesn't inject CO2 when the lights go out. Again, the 3 year warranty (as compared to 6 months with some others) gives me some peace of mind; if it should fail, I still have about 2 more years to return it. Worth every penny I spent.