I think the biggest knock against the post-64's was that they switched to a push-feed bolt, instead of the Mauser designed claw extractor! If indeed this was the only change they made, then they got a bad rap!
The Remington 700 never had a claw extractor, and no one ever grumbled about them!
I have two of the newer M70's and they are as good or better than other guns in their class and price range! Good luck on the hunting!