The sight lines from the top levels of NFL stadiums are usually pretty poor. University of Pheonix Stadium is no different than the others. I had 450, row 16 for the Green Bay Packers game in January of 2010. That was the year when we actually hosted the Packers for two weeks in a row; the final home game and then the Wildcard game during the playoffs a week later.
I felt a little crammed into my seat. How much leg room you'll have depends on the size of the individual. I'm 6'1 and was hoping for more room for my knees. At least these seats aren't bleachers like they are at Sun Devil Stadium.

The crowd atmosphere was amazing, even on the top level. Cardinals fans really stand behind the team when they're amazing as sad as that is to say.
Fortunately for Cardinals fans sitting on the terrace level, you can ride escalators up to the top, no stairs and no ramps to climb. Keep in mind that the escalators lead upwards during the first half and downwards during the second half.