I have a RA XCR with the new gas system and a heavy barrel, I do like the advantages of the new hand adjustable gas system, but the rifle works fine without it. I am going to get a light barrel for mine, I have had a light barrel then I switched to the heavy barrel and I now plan to switch back, because in my experiance the weight of the heavy barrel is not worth it staying cool longer. I also found very slight if any differance in the accuracy of the light vs heavy barrel, but I dont fire it from the bench unless I am sighting in an optic. I hope this helps.
Heres Mine