I've been on GTA for several years, and I am registered on the yellow, although the format gives me a headache. It would be PCP or HPA, no springers for me.
I started out on PCP's and made the switch to rimfire because of the complicatedness of air. You have to refill the rifle every time and sometimes sort pellets, bad BC's, prohibitive startup cost, etc... Rimfire was the better option for me because I can grab my bullets and go shoot for a whole day without ever having to leave my shooting position except for going potty. I can shoot untold amounts of ammo without having to worry about shot count, poi changing, air pressure, etc...
I also don't have to carry a tank or pump to go shooting. I can grab my gun case and stay out for days without having to worry about any extras.
I vote 22LR all the way. Pellet guns have a place, but are more novelty now than much else with all the extra gizmos you need.gun)