mostly fine IMHO
not to continue to contradict hobbes but I have seent pretty good performance as well for the most part.
on a good day with decent/good paint my sniper II shoots +-2fps.
that is after I rebuilt the reg.
I had been getting strange performance from it before the rebuild. I could chrony in at +-2fps but then I would let it sit untill the first game and fire a few shots and then have my velocity drop to 140 fps or less. The reg seat was missing a decent chunk out of the side and would occasionally just not seal. The pressure would build up and pretty well seal my valve closed.
for setting the output pressure on these I recommend getting a spare ASA/bottomline and putting a guage on it (0-1500). then you can sit and tune your pressure with out even having it mounted. You will need to know the pressure that your valve/spring combo will like the best or just turn it to 450 as a general setting for a cocker/sniper.