Diffey is very professional, and does a good job in a technical sense. But come on folks, someone who is more comfortable with F1 doesn't need to be calling NASCAR. It is just a weird fit. Almost like if you would have flipped to a F1 race a few years back and had Buddy Baker and Ned Jarrett on air. Just doesn't fit.
Overall, I like FOX much better than NBC. Allen overhype's the simplest of things. Burton is well, Burton. And Letarte just seems in over his head. Personally, I would rather see Kyle Petty back in the booth. He is not afraid to criticize, and you never know what he may say next.