Roy

I have not used manual valves for some years since I made the switch to electronic ones. I have used 5 different types, Jet-tronic, Orbit Evo, Xicoy, Airpower and Flyeaglejet. Not at all sure what you mean by drift. They have all worked without any issues and it is frankly difficult to see much difference between one and another. The Jet-tronic ones that has the safety feature of venting the air from the U/C pistons I think is the best as it conserves air in case you have leaky cylinders. I have never used the all in one systems as they do seem to be more problematic.

John