CO2.. Only because I didn't have the kind of gun that you should run Nitro with
Smart Parts Ion-
New Designs Bolt, Q-lock
Smart Parts QEV
Blue HaloB w/ Rip Drive
Light, Sexy Looking, Small
The threads can be a bit stubborn the first few times you use it.
Okay so this is the first Nitro tank that I've owned and I love it. The differences over CO2 are great, but I'm sure everybody knows that by now. I think Empire has made a great tank here, I got the 45/71 LP tank for around 220 and it was well worth the investment. The tank is easy to tuck, its smaller than even most 45/68 tanks, it's light, and it's just nice to look at. The finish on the tank itself is really great, I wish i could just play w/o a tank cover so I could look at it all the time. Efficiency is good, i can run through about 1400 shots on this tank with my marker set up the way it is. But when I was running with no QEV or bolt, I was averaging 900-1000 shots with my PSI at around 160. Another really cool feature is that when the tank has no air in it, you can unscrew the reg so that it can get through airport inspections, which I've already used once on a trip to Florida. The only real problem i had with this tank, is that it is a little tough to thread the tank the first few times. Once you've put it into your marker a few times, it gets easier and eventually just slots right in. Since it's one of the few investments I've made into paintball that I haven't had any problems with, I'm going to give this a 10 out of 10. Definitely one of the best tanks you can get in the 200 dollar price range.
Definitely buy this tank. It's not that much more than a Stubby Crossfire, or Nitro Duck tank of similiar capacities, its a little bit larger, but you will have no leaks or problems out of the box with this tank.