So what is the better choice here? RRA Coyote Carbine Upper http://rockriverarms.com/index.cfm?fuseaction=category.display&category_id=417 ARPerformance 6.8 SPC II MW SS Upper http://www.ar15performance.com/inc/sdetail/1978 I have two RRA rifles and am familiar with them. I've had good luck with them. But on the surface, the ARP upper looks like a nicer upper for a better price. Am I wrong on this? Which one of these should i go with or is there another brand that i need to check out?