No offense but why does it have to be either spikes or stag? There are plenty of others that are good quality. Most are forged at the same places anyways. I have had several different AR's and they were all good. Ranging from colt, dpms, sig, and diamondback. Everyone have been great. Great fit and finish. To be quite honest my dpms has the best fit and finish out of then all. And there are people that say dpms is the worst. But that isn't saying that my colt isn't good. Or my db and sig. I love them all. And they all work flawlessly.
I just got a upper and lower from Aero Precision they are very nice. I have heard that Aero Precision actually does some of Spike's stuff. Either way a forged lower is a forged lower.
