If AR-15 owners have a problem, it's that there are almost a dozen different premium barrel manufacturer's and they all make excellent products. What John Holliger is saying is that a properly machined and installed barrel from any reputable source is going to shoot just fine. 90+% of all customers won't be able to tell a Krieger from a Wilson. I have several Krieger barrels and they don't outshoot John's barrels. In fact my best barrel day in and day out has been a WOA 18" SPR profile 1/7.
Wilson barrels are virtually deadlocked with Douglas, Criterion, Shilen and Pac-Nor when it comes to initial quality. They are air gaged the same way Douglas does their premium barrels.
I suggest you by several barrels and compare them using match grade ammo. My experience is they all shoot great with premium bullets. All of them.
I own Shilen, Noveske, White Oak, Rainier, Pac-Nor, Douglas, Bartlein, Lothar Walther, Compass Lake Engineering and several rack grade (LMT, Colt) and every custom barrel easily shoots groups under 1" at 100. The rack grade barrels flirt with an 1", usually 1.25" Quality ammo makes the difference. I don't shoot fmj's.
I can't recommend one brand of barrel over any other and that's my experience with over thirty years participating in NRA tournaments. I hold a Master classification and started competing 1983.
I suggest you by any barrel you want based on profile and perceived value and be happy that we have such high class problems.