A couple of guys we played with last year used AC's. They shot really nice. But from what I've read and heard, they are the "tinker-freaks" gun of choice. They are more complex than most markers out there. Which you probably know first hand by now!
We play in a wooded area between Aurora and the Airbase mostly. It really is the perfect place, it has 3 levels with lots of trees, tall grass, bushes....Sand Creek runs through it to. You can really get some incredible games out there. I've also just been introduced to a group of guys that play near Colorado Springs. I'm going to get together with them soon to play as well. I don't exactly know where they play, but it is outside.
If you live out here, we're more than happy to have you play. The more the better. Last year we had around 10 to 15 people pretty consistently (almost every weekend). We should start real soon, so let me know if you're in the neighborhood!