LOL...as stated in the three previous pages and many, many other threads, the debate is very personal. I could throw in with WA, an old school classic, but you know what?? Get out to some games, and handle a couple of different GBBs. Check out a couple of reviews on the one's you find comfortable handleing, and see if there are any upgrade parts available for them. Then decide if it is in your budget.....
Personaly, I own two KWA M9 PTPs.
-Great out of the box (good for field use right from the go)
-Reasonably good accuracy using 0.30 weight BBs
-No upgrades available
-Mag availability is random at best (and pricey if you buy direct from KWA USA)
I have owned a WA SV Infinity...rather pricey, but an amazing gun. Parts are getting harder and harder to get...