I've done it once, and stayed at the AKL. We spent a lot of time at the resort actually. The crowds were very high - so we'd go to a park, and usually head back to the resort later when it go too crowded. The one exception was NYE when we did an illuminations cruise, then took a cab back from the Yacht Club.
For that week, if it were me, I'd stay onsite. And if it were me, I'd stay at the Boardwalk area. We love walking around, and there is so much right there. I'd do offsite any other week, but for that week, I'd recommend onsite.