Love love this stock configuration. I mainly purchased it because of the options. Installation wasn't too difficult. You should know that permanent modification to your gearbox and receiver will need to be made. Performance has been great. With a 12g cartridge I'm getting 163 shots. I have the regulator set to shoot at 1.2 joules. The last 10-15 shots are noticeably reduced in performance. I have ran a 90g cartridge and used a remote line as an expansion chamber and was able to get 1400 shots with the same joule rating. The last 70 shots were noticeable reduced in performance. I wish there was a way to see what psi your regulator is at without having to chrono it. I did have one instance using c02, were the regulator seamed to have frozen up. It happened during full auto trying to mag dump. After a couple of minutes it started working again. The c02 works great on semi and full auto, however if you try to mag dump it will probably freeze up on you. If you want to loose the line, shave some weight off, and have the flexibility on which type of air to run, then this is a great option.