Originally Posted by mack_turtle

no one is ever going to have a definitive "better" answer. depends on too many variables.

My current gravel bike will work with 650B 47mm tires or 700C 43mm or so tires. I went with 650B and 47mm WTB Ventures because I don't want narrow tires to limit the terrain I ride. 42x17 gearing is working well for that, but that's the topic of a different conversation.