CO2 vs. Green Gas

I'm doing research looking for a pistol, and I still can't decide between CO2 and Green Gas. I've only ever played outdoor games, typically during the fall and winter so CO2 seems better. However, I've heard that CO2 requires more maintenance, is harder to change cartridges during games, and has less options for gun styles. What would you guys recommend for me?

MORE MAGS!!! MORE PISTOLS!!!
Get we tech ones since they probably support both gas, read the description and watch some youtube vids before you buy anything.

From what I've heard, WE Tech pistols break fairly easily. The store I go to hack home even stopped carrying them because of how much maintenance and work they had to do for them.

They have decent glocks (which is all I care lol), and a lot of upgrade parts available. we tech and tokyo marui probably have the largest range of pistol models you can think of, other companies most likely just own a couple models. sometimes a company could have good quality guns but makes shitty mags, so compatibility is something to consider just in case you want to change some parts. And the fact is that gas guns breaks a lot, CO2 or not you will probably have to take it apart after every game just to be sure.

Right now I'm between the Green Gas KWA USP (or M93R) and the CO2 KWC C96.