My buddy and I did it this past August and it was awesome! You hike a big loop through 4 passes that are each around 12,000 feet. Absolutely Gorgeous.

Pros:
Loop so don't have to have 2 cars or hitch a ride
Easy access from highway and city of Aspen
Clearly marked trails and designated camping sites
Challenging (most people do it in 4 days, my friend and I planned on 4 days but hiked faster than we thought and did our first 2 days in 1 day)

Cons
Can be crowded
Requires a bear canister (adds quite a bit of weight)
If you don't like hiking steep ups and downs it's not the trip for you