If you have only seven hours, I don't know that I'd recommend trekking up to Scottsdale, especially if you are intent on using public transporation. The Red Line bus will take you directly from the airport to either DT Phoenix or DT Tempe.

http://www.valleymetro.org/Transit/7...html#wp1111497

The DT Phoenix Hyatt has a revolving restaurant on the top floor. I am sure the food is less than stellar, but it would give you a bird's eye view of the valley.