I've gone through a few different lowers over the past few years. No real reason, I just couldn't settle on what I wanted in an AR.
I started with an M-4 Stag, traded the upper for a 20", sold it to build a 204 with a DPMS lower. Sold that rifle to build another 223 with a Tactical Innovations lower, sold that complete lower to buy a billet lower from Seekins Precision to put another M-4 together. I assembled a couple Superior lowers for a friend and his boy, and assembled a Rock River for our youngest boy with a lefty upper.
So that makes:
Stag, DPMS, Tactical Innovations, Seekins Precision, Superior and Rock River.
The amazing thing is,,,,, they all had great finishes, matched all of the uppers flawlessly, and the LPKs and buttstocks fit fine.
So I guess what I'm sayin' is, get the one you can at the best price you can get it. Buy a good to great trigger and spend the extra money on optics. I just don't get the "gotta have a Colt or Bushmaster" mentality. The resale is better on those rifles, but you spend more to begin with so the actual percent of resale is all relative, and better sometimes with the "lower quality" lowers.
Spikes Tactical still has their lowers on sale for $90, I've looked at them at a gunshow in Texas and they have a real nice finish and look great with their spider logo..