We have never done NYE at Pleasure Island, we usually do EPCOT. A few years ago my boyfriends niece, she was about 23 at the time, did NYE at Pleasure Island with her boyfriend. She said it was a total mob scene. We were at EPCOT the same year and yes we had crowds but nothing like she had. EPCOT is so large and there are so many out of the way places to go no matter how bad it is (and we have been there most NYE for the past 4 years) you can always find someplace to sit and relax. Besides, on NYE they have the best IllumiNations. What ever you do, have fun.
Linda