Young Guns - Bigger Pro-shop and better staging (equipment pick-up, etc) areas; smaller fields (in general); same travel time; good quality rentals; friendly staff; huge parking lot
Quest For Adventure - Good variety of terrain; low prices; longer travel time; lower quality rentals
I've been playing since I was in University (more than 10 years now) and I've seen the fields around Edmonton develop over time. PAG (or Cammo Coulee as it used to be called) has come a long way since then.
Some of the pros are:
1) They have an excellent range of terrain and field sizes, which can accommodate small to large groups and noobs to hardcore players.
2) Their prices are reasonable for renters and you get decent quality equipment (including pods most of the time) for your buck.
3) The refs are very experienced and are very conscientious about safety, which is good if you are sending out a bunch of noobs or young kids (or young noobs).
4) The staff is helpful and friendly (if you follow the safety rules) and this shows in the range of players out there.
Some of the cons are:
1) The staging area is small and hasn't changed in many years and this can make getting a big group sorta chaotic.
2) Facilities aren't great, but you're out there to play paintball aren't ya? If ya don't mind the porta potties, you'll be fine.
3) They don't allow walk-on paint, which for equipment owners kinda sucks. You can buy bulk from PAG, but it's still not as cheap as bringing on your own.