Nothing I have used compares, although I'm not big into semis.
1995 Thruster Ready Vector. Gas thru stock with WGP regulator.
This gun is great. It is really consistent, turns heads at the field, is very accurate, has a very nice trigger pull, a great stock barrel, doesn't really need upgrades, good rate of fire, and a very reasonable price. This is by far the best gun for under $300 and compares favorably to the higher level guns. You can get an aftermarket barrel from BOA, but you don't need one.
This gun is very loud, but that's not a problem for me. Who cares if they hear you if they have already been hit by the paintball? The only problem I have with the gun is that it is not very efficient. It also leaks out the 4-way a little, which adds to its inefficiency.
It's a great gun. If you can get your hands on one, buy it up! Best value I've ever seen.