What's the worst part of ownership of an AR? Well, to me it's cleaning it. I'm curious how the piston recoil kits compare (in shooting) to the gas system?? Bit out of my budget but was something I was thinking about as I think of the upper I want to build down the road.
Personally i don't mind the cleaning but I've heard good and bad about them, The good is the easy cleaning the bad being prone to breakage however IIRC a lot of the breakage was on the earlier versions.
Granted they do make cleaning easier, but think about this. There is no "mil spec" when it comes to piston systems. Each manfacturer has their own system and none of them are the same. If you buy one and the maker moves on to a different design, will they still make their old pattern? If you break a part, you can't shop around for the best price on that part, you will buy it from the manfacturer and pay what they want. I have looked at getting one myself, but figured I could use the money on something better. Just something to think about.