My 550.00 delton shot fine against my 1000.00 colt 6920. I couldn't tell the difference.
What does A bit more "in Spec" mean?
Either the upper meets specifications or they don't. the PSA entry level upper and the Del-Ton uppers are in the same quality class. I've got both, can't tell the difference.
The idea of getting the entire kit from FBT is a great idea. It ensures all the parts will work together (that way you don't end up with a mil-spec lower and a commercial spec buffer tube - stuff like that)
Just because you can't tell the difference, doesn't mean there isn't one. The term "mil-spec" doesn't mean a darned thing. The PSA DOES more closely follow the Technical Data Package (TDP) for a military rifle than the Del-Ton, that's a fact. No AR on the market follows the TDP 100%, but the Colt LE6921 does so more closely than any other AR on the market. No, the TDP is not the be all, end all benchmark for an AR, but it does set a definable standard that substantially exceeds many of the "bargain" AR's on the market. This is based on reliability, durability and accuracy combined.
To the OP, if you want a Del-Ton, get a Del-Ton. If you want FBT, get FBT. If you want Palmetto State, get Palmetto State. If you want Colt, get Colt...
I ran a firing line supervised by 5 active duty soldiers last weekend. I oversaw the firing of about 2,800 rounds through 6 AR's from 4 different manufacturers in about 3 hours. All of them were inspected, cleaned and PROPERLY lubricated prior to firing and periodically throughout. I called the two that choked and quit about 10 minutes before they did exactly that.
All I'm saying is that for a casual shooter who will go out and put a magazine or two through an AR in a casual setting, clean it and repeat in a month or two, nearly any AR will do. Some will break before others and some won't quit until they're worn out. Just don't have unreasonable expectations of your purchase, clean, inspect, lubricate and enjoy.