I bought my PA10 a while back, and have had it a couple years. I was blind as a bat, so to speak, when I bought it. And, I did what 98Z5V said a lot of folks do. I thought it was over gassed. So, I put on an adjustable gas block. I added tungsten weights to make it a H3 buffer. I added a couple quarters in the tube to stop the BCG from hitting the rear of the receiver. I never changed out the gas tube for a longer one, and I have never even looked to see how long it is. I've never changed out the recoil spring either. I guess I'm pretty lucky it runs good. Well, it seems to run good anyway, to me. Everything I've done to it seems to work, and work pretty well. I've not had any problems since I've made the mods and gotten the gas block adjusted.
So, I guess my question is whether there are two ways to skin this cat? Or, am I shooting a rifle that likely will need further modification in the future? I do expect to have to change out recoil springs at some point in the future, like you would with any semiautomatic firearm. So, I wouldn't really count that as a modification unless I changed to a different spring other than what PSA put in it. And, if I did, couldn't I just readjust the gas block to accommodate the new spring?