Although I love the idea of seeing your fiance for the first time as you walk down the aisle, I think it is more important to make sure the event flows for your guests so they don't have to kill hours. I wouldn't want to have my wedding in the middle of the afternoon and then have my guests have to entertain themselves for a couple of hours (while dressed up) and then come back for cocktail hour and reception. It is especially an issue for those brides that are having their weddings in the "winter" months where the sun sets earlier but you don't want the night to end too early. For my wedding in November, the sun will set just after 5pm. Thus, to have pictures after the ceremony would mean having the ceremony 3-3:30 so we could get pictures from 3:30-5pm. But we wouldn't want to have the cocktail hour until 6-7pm so the reception could run from 7pm-10pm. That would mean guests would have to find something to do for 2.5 hours.
Instead my plan is for pictures from 2:30-4:15 (then back to the room to freshen up), sunset ceremony from 5-5:30, pictures with entire group 5:30-6:00, cocktail hour 6:00-7:00, reception from 7:00-10:00. That will keep everyone together and celebrating, but it will also give guests an extra 2 hours of the day in the afternoon to enjoy their vacation at the pool or beach. One other point - the photographer will be able to do a MUCH better job of capturing your fiance's reaction in a controlled first look environment.
Obviously, there is no wrong answer to this question - only personal preference.