Well I guess it depends what you are looking for. I love my Tac One. But if you shoot ALOT it may not be for you. They do tend to be air hogs but they're accurate, quiet and easy to maintain.
The level ten needs to be set up but there's good instructions on AO about that. All the info you could ever need on an Automag is on AO.
You need HPA to run the Xvalve in the Tac One, it's recharge rate is so high that it freezes with C02.
Hmmm, where to start with all this... Alright, Mags are made up of different parts and you can swap alot of them around. There's the body, the rail, trigger frame, valve/bolt, & vert adapter.
If you wanted to use C02 you could swap the X-valve out for a classic/minimag/micromag/A.I.R. valve and it would run off either type of gas.
There's two "styles" of valves.
The Classic/Minimag/Micromag A.I.R. valve. Can use either type of gas and I believe is more efficient.
Then there's the RT valves. RT valve/ReTroValve/Emag valve/X Valve. These become reactive when you use an adjustable bottle reg. to feed the valve around 950-1000 psi. At about 3000psi, the RT valve will shoot about 32bps; fully mechanical
If you grabbed a marker with a ULE body and wanted the Tac body you could swap though too. Same with rails and trigger frames. I have a trigger frame made by Logic and a rail made by RPG (Magsmith), they change the look/feel. Some are milled for weight reduction.
Here's a pic of mine & below are some links to some cool things.
http://www.zakvetter.com/paintball_vide ... s_test.mov
http://www.zakvetter.com/paintball_videos/34bps.mov
http://www.zakvetter.com/paintball_vide ... ations.mov
If you have anymore questions ask away and I'll be more then happy to help. I'll even let you run my Mag at a game.