Well, there are more informed people here to help, but my personal experience went like this: When friends at work found out I was playing paintball with my son, I was given lots of old stuff they weren't using. Included was an SL68 Tippmann. I also found a cheap Tippmann A5 semi on Craigslist that I used all the time. I started using the SL68 a little, and realized how much fun it was to pop someone "old school".
Then I found a used 2000 Autococker parts gun and converted it into a pump. I don't care how outgunned I am, I'd still rather play with that old autococker than anything else I own now, including an Angel G7 Fly.
I'm convinced I'm a becoming a better player every game. The G7 just made me sloppy, and playing that way wasn't as rewarding.
Anyway lots of great pump guns out there. Explore around the Pump Section and you'll get lots of advice.