I play mag-fed, semi-pistol exclusively. Not only do I find it to be the most fun, I also shoot less paint than I do with a pump. I tend to double tap, get the elimination and move on whereas with my old trusty SL68 I'd have to pump before the followup often missing the shot and then extending the exchange and that's when the ball didn't just roll out while I was improving my position.
Open class pump holds no appeal for me. I can auto trigger my hopper empty but what's the point?
I've considered purchasing a stock class marker. I think stock class would be fun if only there were local games.