I'm in the process of looking at either an Armalite AR10 or the Rock River A4. Both of these guns have the 20" chrome lined barrel and the 2 stage trigger. I really want something that will be a good investment, do any of you have any input on this before I decide? As far as I can tell, the only real difference is that the Rock River takes FAL mags. The rock river is also 200 bucks cheaper ($1199). I am definitely leaning towards the RRA, but I wanted to see if I'm missing something here?