Theres nothing really to compare a Double Barrel paintgun with, unless its home built. I own a Nasty Hurricane (wood stock).
Two Barrels (fixed), Two Motorized VL-2000, 20oz tank ran on remote.
When getting a Nasty, motorized loaders are a must, something that will feed the paintballs quickly into the breech. Most (if not all) Palmers markers are fixed barrels so thats not a problem, and they are honed and very accurate.
Its a wonderful way to collect attention to yourself. Its setup very good, with reg, 4-way, hammer and trigger. Its one of those guns that you don't see every day at your local field, and they are just wonderful at big games.
They are not tournment legal. Some fields won't allow you to use them because they shoot more than one ball per trigger pull which is alright as long as your not on the recieving end. I know my Hurricane is heavy without two loaders of paint and tank (which I've ran to remote so that takes a lot of it away).
I think its a great gun, Palmers makes some of the greastest markers on the planet and I'm not selling mine anytime soon. I enjoying taking it to big games and watching the surrounding players, either ask me what it is, where I got it, how much it was and run get their buddies in excitement only to find that I'm on the other team, lol.