There are a lot of different spec 6PPC reamers out there, and I doubt many would claim one as “the best”. You need to consider things like where you are going to get a sizing die, and how well the chamber body will fit a die. Some have a reamer specked to fit a Redding small base 6PPC die for this reason. Also, do you plan to shoot boat tail bullets? If so, the 60 thou freebore in many reamers may be too much and you may want to consider 45 thou or even less. Lastly, many reamers today have thicker necks such as .268 to .270. I went from a .263 neck to a .270 neck and find turning cases easier, with no loss of accuracy.
Sorry not to directly answer your questions, but these are a few points you may want to discuss with your chosen reamer maker.
