http://www.ar15.com/forums/topic.html?b=3&f=118&t=245739
This is the link to the thread I started on almost the same question. If someone can make it hot I would appreciate it. And tell me how while you're at it........
I decided to go with ARFCOM tradition and "Get Both" - RRA and Stag.
To be perfectly honest, I'll think real hard before buying Stag again. It may not have really been their fault, but the pistol grip screw hole had the threads cut too tight. I couldn't screw the pistol grip screw in deep enough, and what I did get was REAL tight. Had to use oil and a vice to hold the allen wrench so I could actually turn the reciever by hand. Even so, it wouldn't go in all the way, and if I had kept turning it I may have ended up breaking off the screw inside the reciever.
My Dad took a look at it and his feeling was they used a very worn tap to cut the threads. He happened to have a tap in the right diameter and thread and recut them for me. After that there were no problems. I was using an Olympic lower parts kit.
Otherwise, the quality and finish were indistinguishable between the Stag and the Rock River. The lower parts build wasn't too bad - very doable - and I have the mechanical ability of a hyper 5 year old with ADD who's doing the pee pee dance. For tools you only really need a light hammer and a 1/8 and 1/32 punch for the roll pins. A vice was helpful, and so were vice grips - but I don't think they're a must. I also used a very small screwdriver - like from an eyeglasses repair kit - to get the front takedown pin with spring and detent in.
I would recommend Eaglefirearms.net. They really were great to deal with. And very low cost.
Either way, Good Luck!
-K