When it comes to custom rifle barrels I'm not sure there is a 'best'. But, there are blanks, made by some, that I'm not interested in using. There are some available, that you don't hear much about, that are quite good. The "best" can be turned to junk without the proper skills, knowledge, and tools.
"Shoots real good!": definition; it didn't blow-up in my face. Not everything can be fixed on an internet forum!
No such thing as "best" when it comes to barrels. All will have a dud now and again. Some have fewer duds than others. Personally, I have owned rifles that have had and shot well with (In alpha order):
I have pretty much decided that as well as the Hart and Broughton shot (and they shot pretty darn well), I'll be sticking with cut rifled barrels from now on.
If Bartlein does not reduce their 9 month lead time on direct-order barrels, they will drop off my list alltogether.
lilja is the only custom barrels i have ever owned. the quality is so superb and the accuracy so outstanding i cannot imagine any other barrel outperforming his. since i live so close to the factory, i have been there and shown the specifics of handlapping, stress relieving, etc. no break-in, copper and powder fouling seems to be repelled and accuracy is way beyond what i can shoot.