For those in 2012, the only ones in DD's company who became NASS squad leaders had applied for and been selected for the position. That could possibly have been company-specific (as most things are). NASS was a lot of work, but DD and a 2013 Mid we know both thought it was a good experience to see NASS from "the other side."
DD had a grey hull "cruise" in addition to NASS. I have heard of great cruises (Pearl to Japan on a sub) and terrible ones (a month tied up alongside in Norfolk with no ground transport). There's probably everything in between, based on what's happening on the ship, how interested the ship is in having Mids aboard, and how much the Mid is willing to go looking for things to do.
A friend who is 2011 did sailing and had a great time. One group went up the coast to Newport, a second group met them there and sailed home.
YPs have changed a lot from year to year. Class of 2011 went port hopping and had a good trip. Class of 2012 went out day cruising and came back to USNA most (if not all) nights.