I just love Arequipa. My 3rd visit here. First time 6 months (volunteering in one of the poorer schools), then a few weeks last August (2012) and just returned from 3 weeks in April/May 2013.
Friendly people, great food, clean, safe city. A lot of great places to eat. Plenty of good bars. The city has plenty to see and it is a launching pad for lots of great places (e.g. Colca Canyon). Put a visit here on your must do list in Peru.