I don't know. My experience with the PTR is reduced to one (1) rifle, and this one rifle I have is especially accurate, and works flawlessly. I cannot say the same with respect to many of the AR10's that are out there. I mean really; $.50 magazines that are built like a brick outhouse vs. $50 mags for the AR10. A proven reliable action, floated match barrel, rugged modular design, the PTR91 presents a better rifle than any AR10 I have shot, regardless of price. Once price is factored in at roughly 1/2 the price of the AR offerings, even with a couple of useful modifications such as the paddle mag release, the deal is easily sealed for me.
But there are those who really like the Large Armalite actions, and I tip my hat to those guys. Nothing wrong with the various large actioned AR's, just not my cup of tea.
Now, once you start talking 243, which is my favorite caliber, unless one were especially lucky to buy one of the PTR's in the caliber a few years ago, the AR provides a viable option, if you discount the Remington 7400 I think it is, and must have a semi auto rifle for whatever reasons.