I'm considering purchasing a Sig 556 SWAT (or one of the newer piston AR's), and I am wondering if any of you who have experience with the 556 system, have a preference between the "patrol" and "classic" designs? I have been doing a fair bit of research, and it has me leaning towards the Patrol model. The pro's seem to be; lighter rifle, not front heavy like the classic, without a significant change in weapon characteristics. The only con I have heard of, is the supposed "increased wear and tear of a shorter system". That said, I have heard the same thing said in the carbine vs mid-length AR debate, that carbine length gas system will result in shorter lifespan of the rifle as a whole. I find that hard to believe, as every carbine length M4 I've seen and used in the Army have been shot-to-sh**, and don't seem to be the worse for it. Thanks for your input guys! P.S. I could care less if you think "DI IS SO MUCH BETTER THAN PISTON, NO NEED TO CHANGE". I don't care. I'm tired of my DI M4, I have no desire to own one, I finally have the want to even own a rifle chambered in 5.56, but I want something different.