In looking at the new wave of piston ARs, I've noticed that each manufacturer seems to have developed it's own unique system. In the past, one of the beauties of the AR platform has been the interchangeability of parts between guns. Do you think eventually the piston systems will become more standardized or will the manufacturers continue to produce distinct designs that are not compatible? I know you can always throw a piston upper on any lower. I'm talking about parts within the upper. Do any of you just think it's best to stick with gas impingement despite possible advantages (if any) of piston guns? Curious to hear opinions. Thanks.