Definitely visit the schools, talk to the instructors and the students. You can also ask to see the airplanes (I did that before choosing a place to rent from), but if you haven't flown much, you may not know what to look for and what's normal.
Many people actually prefer the "club" feel of PFC. Instructors seem to actually care more about students, etc, and there's a more friendly atmosphere and more interactions between students. I would have picked PFC probably if not because of the price. Being more "club-like" also doesn't mean they are not professional. They have an agreement with BCIT and train all the BCIT pilots. Training quality is definitely not any lower just because they are a club.
Sea Land Air has a small fleet and scheduling does become problematic in the summer (busy times), especially if a plane or 2 are in maintenance. That said, I find that I can usually get anything I want if I book 2 weeks in advance. That's something you wouldn't need to worry about with a school with bigger fleets.
SLA is more commercial and business-like, which I don't like, but that's personal preference. Their airplanes are very nice, though. The Diamond DA-20 (their standard training airplane) is much nicer than Cessna 152s in just about every way - better visibility, slightly faster, awesome climb rate, extremely high glide ratio in case of engine failure, very benign stall/spin characteristics, and are much newer (nicer interior, etc, doesn't matter too much for training, but passengers really like it). And it's about the same price as 20 years older C152s (last C152 was produced in 1985, so the newest C152s are 28 years old now).
For me, I'm willing to have to book 2 weeks in advance for the nicer airplanes, but if your priority is to get the licenses as fast as possible, PFC or PRO are probably better.
I am not an airline pilot. Just a private pilot flying friends and family around on weekends for fun. My day job is something totally unrelated to aviation (electronics engineering).