We've run Superior, Alloy USA and even RCV's in the past. What I can tell you is that they all work well so long as you make sure they come with full circle clips. RCV's are nice but, not worth the extra $400 or, at least not in my opinion. Sure, their joints are strong but really, they're too strong and will just push whatever break you have deep inside the shaft or onto your ring and pinion. Trust me, I have seen it happen. Factory shafts typically break due to their c-clips getting pried off and without them, nothing will be left to keep the bearing caps in place. Once they fall out, you will have an axle shaft break. Full circle clips, what are typically found on standard chromoly shaft will prevent this from happening. This is what we are running on Rubicat now.