They are a damn consistent rifle as "Waldo"[Gordon] says with the fettling he mentioned.
AT needs to be out to do them not a hard job.
For myself I have fitted 5 "Rob Lane" regs , two to my own rifles. All depends how far you want to go and basically it just gives a bit more confidence in not having to worry about a sweet spot, mine will shoot from 190bar down to 100 [with a fitted EV2 cylinder] never counted the shots tbh but its superbly consistent with unweighed pellets.
The easier path is the fettling Gordon advised.