My biggest concern with Pep is that he's never managed in a situation where he doesn't have elite talent that the majority of his opponents simply can't compete with. How will he do developing young talent up and down the roster rather than rolling balls out for the best team money can buy? What will his tactics look like when his team appears overmatched on paper?
His results obviously speak for themselves, but this is a very different job than anything else he's done. That said, they need to go for it. Landing that kind of a name is a massive statement of intent that can only benefit US Soccer.
If he declines, I would really like to see BJ Callaghan get a look. His Nashville team has been excellent and he also had the USMNT playing very well his brief interim stint between Berhalter 1 and 2.