One needs to look a bit closer, than just reading off the famous rob_s chart.
Simply looking at HP and MPI testing is a very narrow basis to gauge the quality of a brand.
For example, Noveske (N4)and KAC employ CHF made by FN and Colt Canada. Is it Colt (USA) spec - NO. Also, the purity and the exact composition of the steel may not be MIL-B-11595E. What is the difference between a 6000 round M16 spec'ed barrel and a 30,000 round European spec'ed barrel for HK416/SG55X or a 10,000 round spec'ed LMG such as M249?
However, KAC does not even HP and MPI, or shot peening their bolts - well, you need to figure out what it bothers you more.
Will I give up a CHF barrel made of good steel for a blue extractor insert or HPed bolt? You need to pick your battle. I can always go buy another bolt if it bothers me.
Or does an extral aluminium liner matter more, for handguards that most toss away anyways?
How about heat treating and other QC that are not talked about?
The Rob_S chart is made up of superficial observations and check marks - the devil is in the details (and the track record, QC and QM of the manufacturer as well as the assembler). Some of the "mil-spec" featurs are useless, some are minimum and some shall be exceeded.
Yes, I agree, eg) Armalite says that they don't need to MPI and HPT each of their bolts because "that's old technology". They only do "batch testing", but how do you prove that?
If KAC doesn't MP/HPT/Shot-peen their bolts, it's because they use different manufacturing processes and parts designs from the typical. Anyone familiar with work hardening and designing parts to resist stress cracking can look at an AR bolt and see points for improvement.
KAC has had the huge advantage (over Colt) of being able to design their parts from the ground up ~ ie) no one actually uses them (SR-15E3 ect), so they don't have to be backwards compatable to rifles manufactured in 1960.
In the AR market, pretty much everyone else has simply copied the Colt product ~ some of the "boutique" low production brands have made undoubted improvements, but they haven't been produced in the 100,000s.
Barrel life-spans as specified: The acceptable standard has to be standardized, ie) that 6,000 rd barrel may be better than the 30,000 rd barrel if the spec criterion were the same, (minimum acceptable accuracy ect).
The number of lands/grooves, barrel wall thickness, means of manufacture, barrel material, thickness of chrome lining each play a part.
To answer to OPs original question:
A "recreational shooter" is un-likely to notice a difference between a Colt and a Norinco. You are better off to purchase a mid-level AR varient and use the balance of money saved to purchase loaded ammo or componants.
After replacing a bolt due to breakage after the 5-8000 rounds of 5.56NATO level ammo fired, consider upgrading your rifle with a Colt, or upgrading it's componant parts yourself.