copenhagen is freaking amazing. visited for about a week, but lived in Jutland for 7 mos. A summer would be a blast -- lots of parks, sights, bars, and cafes on top of beautiful 70 degree weather. I'd do it again in a heartbeat.
Will be there next week. I have been a tourist to Kobenhavn about 6 or 7 times and lived a summer just outside the city. Everything you read on this thread is correct. GREAT CITY! Do it..