I'm pretty new to the pump part of paintballing, but i have used pump cockers before, but didnt like the idea of using a hopper so i went with a Phantom. The grip frame comes down to personal preference, i liked the 45 partially because i can get a set of grips for it. I took out my phantom for the first time yesterday and was quite surprised by its performance. I was told the Co2 wasnt going to be as efficient as it would be in a couple of months, but i was averaging 35 shots off a 12 gram, velocity was generally +/- 10 (it was 55-60 degrees out). Accuracy is easily the best point on this marker, i liked my autococker for its accuracy but this was landing shot on top of shot. It does take a bit getting used to the idea of 10/15 shots if your used to playing with a big setup, but you quickly adjust. Also theres no need to worry about batteries which makes this all that much better. It's a cheap alternative for playing, that also improves your skill while keeping paint within an affordable budget.
Conclusion:
I'd reccomend it to people who are interested in pump play, its not too expensive, and theres not really any reliability issues.