The advice you've received is the best. Don't arrive before 11:00 a.m. or you will just sit around. The check-in may be faster but you'll just sit after that.
A supposedly "seasoned" cruiser wrote a review of their cruise. In the review she stated that they arrived at the pier before 10 a.m. and was irritated that they had to sit for two hours before being allowed on board. I just thought "duh". After the number of cruises this person had taken I think they would have figured it out by now.
Take care and have a wonderful cruise.