This is one of the best airports in the USA. I aim to check in there about 1hr 15 minutes before departure and that's heaps. So if you have bags, I really would not check in before 2 hours beforehand.
I'm hoping dylanks will spot this thread, since I'm sure he's better at giving local advice, but actually there is a landside branch of Chelsea Kitchen in PHX airport, T4. It's probably the best airport restaurant I've ever come across. Not sure I'd want to have a special event in an airport, but if I had to, then it would be PHX and it would be that restaurant!