Hey Jake I really appreciate the good detailed information.

I do have Dacron sails now and after reading all the posts here, the Mylar main, Dacron jib combo is what I'm leaning toward.

I will take your advice and talk to some more Isotope sailors on the class rules/legalities for square head vs. pin head but as far as I know, there isn't any modification factor for having a square head sail.

Some of the Isotopes have square heads and others have pin heads-I believe the Isotope fleet is not as strict on that point as other fleets may be.