Since living in Scottsdale over the past 5 years, just minutes away from the library I have taken to calling it my home away from home as I pursue a masters. The hours are great, the staff as "geeky" and awkward as you'd like them to be and the people watching (when reading and typing just gets too boring) is on par with the mall or any airport I've been too. The quiet section is usually well respected and there are always the rare few people who seem to think they are talking on their phones in their living room but there is usually plenty of seating, and at worse study rooms for those who need to work in groups or really need some peace and quiet.
p.s. Keep an eye out for the "fisherman". He's a guy (I believe) that comes in with a Home Depot bucket and a trench coat, sits near the windows and curses up a storm at himself, and presumably the world and it's consipracies. Priceless though at times distracting.