....but, I have owned and/or shot Broughton, Hart, Lilja, PacNor, and Shilen. The first 2 custom rifles
I owned both wore Shilen bbls. AFTER I had Shilen rebarrel my actions, I heard some talk about how they USED to make great barrels, but got more into quantity than quality and had quite a spell of making some bbls that perhaps didn't meet quality known to be associated with the name Shilen. In fact, Lex Webernick, of Rifles, Inc. used to ONLY use Shilen barrels but due to some concentricity issues, he switched to Lilja and hasn't looked back.
As for my 2 rifles with Shilens, well, lets just say that I'm more than satisfied, and would quickly rebarrel both guns with Shilen again. Broughton had not yet come out with the 5C barrel. I've heard nothing but great things about this product. The folks at "Best of the West" have tested a LOT of custom rifles with the Broughton bbls as well as most others and related to me that this is "the best" long range rifle barrel made, in their opinion.
One of my 270s wears a Hart. This is a truly accurate bbl but was a beyotch to clean and break in, which goes against their own website's recommendation stating that break in is not necessary. Of all the bbls I have and have had, the PacNor was by far the fastest to break in and to this day, is the easiest to clean and keep clean.
My Broughton 270 (700 action) is probably the least picky rifle I have. I've had it for 5 or 6 years now and have yet to shoot anything through it, test loads included, where it grouped greater than 1.25" at 200 yards from a solid rest. However, I have only used reasonably known combos for a 270, like the various 4831s, 4350s, Re19/22 and 130 or 140 grain bullets. Greg Richards of Hobbs, NM built this rifle for me back when he owned and produced Broughton bbls. He sold the company to its current owner. The stock is a Rimrock from Jim Borden. Despite the popularity and truly accurate reputation of McMillan stocks, it is my opinion that Rimrock stocks are their equal.
Many reputable riflesmiths would tell you that among the elite and well known barrel makers, you probably could not tell who made what barrel once it is fitted to the rifle properly. As previously mentioned, the bbl maker is at the mercy of the quality of steel, the smith relies on the quality of bbl, and the rifle owner is at the mercy of the skills of the smith, bbl maker, AND steel producer, such as Crucible.
The good news is, you probably wouldn't go wrong if you tossed a coin for any of them that have been mentioned.