Oh my gawd, I have never ever cleaned the gas tube on my ARs! Does that mean I'm going to have issues with them?
One needs to also remember that piston designs are all different and proprietary, and so are the bolt carriers for these piston guns. Going piston means you kiss good bye to two things: raw accuracy and parts interchangability. If these two things are not a concern for you, then a piston may well suit your needs.
Oh and there is the problem of carrier tilt in piston ARs. So maybe three things.
