I have a hobie-bob sitting around, but I'm never gonna use it...it just looks so amateur. I understand if you are a beginner that you need the peace of mind it provides, but once you've learned to right the boat even if turtled, then you've got it.
You have to realize that not everyone sails in 30' deep water. Driving you mast and sails into the bottom is a little hard on equipment. You are correct that a sealed mast is important, but for some of us that sail on shallow waters, a mast float is good insurance. Probably not a "must have" but I'm glad I have it.
Jack - proud to be "so amateur" looking
Fort Loramie, Ohio
P18 with Prindle Bob