I haven't ever had Zaxby's—but it's probably a lot like Guthrie's sauce which, now that you mention it, is basically fry sauce plus black pepper (and a lot of salt, I think). The black pepper is what's missing from the fry sauce here—it's a little bland. Next time I have it, I'll have to make that modification.

The other Utah food that I've been told about but haven't yet experienced is "scones," which apparently are nothing like scones as we know them. They are some kind of deep-fried thing, like donuts but not really. I'll certainly post a report once I've tried them.