Really? So you don't care about whether they are reliable, accurate, ergonomic or balanced? How would they be "on par with" AR15 piston rifles without considering those issues?
Good call, I did contradict myself.
I'd ammend that by stating that I presume that ACR and SCAR are more reliable and durable etc. than what I am currently running based on what I've learned about them so far, but are they on the level of the established fan favorites of the type. I don't want to go the trouble of finding some examples to borrow, or rent without conferring with the knowledgeable as to whether or not they are of equal quality