The Gas Gun matches are a lot of fun, they are different from the PRS Bolt gun matches in that the ranges are shorter, targets bigger, and pistol gets mixed in. At the Kahles Gas-Gun match at Peacemaker, the stages of fire were not that different from the PRS matches they hold there. The distances were mostly in the 300-500yrd range with generous targets. The individual stage pace is faster than a normal PRS match, but slower than a 3-gun match, where you need to snort lines of pre-workout between stages to keep up.
Some of the stages were unlimited round count, which definitely changes the "game" if you chose a large frame AR, the guys shooting AR-15's would just load up 30rnd'rs and just shoot until they got the hit. So, for the stage planning on a 15 target stage allows for 1x miss/target without a reload, vs. .308 mag of 20rnds that allow for 5x misses total. There was only one stage with targets beyond 600, so while the .223/5.56 might lose out to a .308 on that stage, it made up for it on the other stages with recoil management and volume of fire. One thing the unlimited round count did influence, is the ammo you brought to the match. If you brought the match minimum of 250rnds, then you could not keep up with the guys who brought 500rnds and shot as much as required to hit the target. This is the part that I'm not sure I agree with, if the match advertises a 250rnd count to complete, the shooter would normally bring a few spare rnds for malfunctions, etc...not another 200rnds! It leverages the professional and Mil shooters, bringing cans of ammo, over the amateur who probably scraped and saved to pay for the rounds and match fee. It also, in my opinion, takes away from the precision part of this style of match since it has a PRS style association and brings it closer to LR Multi-gun. Still a ton of fun though and definitely challenging.
The addition of pistol definitely messed up a lot of dedicated rifle shooters, if you even dabble in USPSA/IDPA/3-gun you could smoke everyone else on the pistol part of the stage and then fumble through the rifle portion and still come out with a better score.
Also, if Tyler Payne from the AMU shows up, you aren't winning the match.