I am looking to stay at the Imp Campsite this weekend. Can anyone tell me how popular/busy this gets?

Expanding on that question, what are the most popular campsites in the Whites? Can anyone rank them, from most to least used? This obviously isn't an exact science, but in planning backpacking trips, its good to know which one I should start earlier in the day, in order to give myself a better shot at landing a spot.