Tuning Huma Air Regulator Question

Humas are probably THE best regulators you can get.

I'd argue that. Yes, they are very good regulators, but seriously no better than others like the AGT, KalibrGun or even the stock regs in FX airguns. The benefit of the Huma is that it is easier to adjust, and very easy to rebuild when it creeps or leaks. 

The chance of them creeping is probably the same as any other high quality reg. I recently bought a used .30 FX Bobcat Mk2, with the factory reg set at 150 bar. It's rock solid at 150, even after a week. 

IMHO though, the best regs on the market are the ones that AGT makes that come in the Vulcan2. I had a .30 Vulcan2 that shot 20 shot strings with an ES of 3, over and over again. Sometimes 4 FPS, but normally 3. 
 
I guess it just depends on personal experience with a relatively few regulators, since most of us can't test enough to render a meaningful sample. The regulators in my RAW, Taipan Veteran, and Weihrauch HW100 have all been excellent. The FX reg in my Royale 400 was not good at all, and I put a Huma in that rifle, and it's been fine too. Based on robust construction, I would guess the Taipan reg might be the best of the bunch. To the OP, you should chrono test your regs for consistency as well as watching them for creep, before deciding on replacing them. A regulator is a simple device, and if it's working well now, it probably will for a long time. 
 
Since you are talking about the crown, and impact, there probably is no advantage switching to a huma reg, as long as the ones in the gun are working good. About huma being easier to adjust, that mainly the correspond to the tube regs in older FX guns, and other brand of guns. I have two huma regs myself, one in a FX bobcat, and one in a taipan veteran. And I agree in thouse guns, they are easier to adjust. I also would mention that the huma tube regs are often smaller than other brands, and will give you some more air available to use in the tube, which also is an advantage. The reg in my impact work just fine, and replacing it would just mean unnescessary use of money.