This argument will never end but I am going to post this link just because. When it comes to gel coat It's all depends on the prep and use. For every article, experience, hear say from someone else, there is another one on the other side of this. I decided to use epoxy after doing the research and seeing first hand failures of polyester resin repairs. When it comes to structure I would rather use the stronger solution. I also use screws to put decking down and not nails.
http://www.westsystem.com/ss/polyester-over-epoxy/
Kyle has more than enough info on this. I am sure he is fully capable of researching it further and making an educated decision. How about we give him his thread back at this point. If you feel it needs further discussion why not start another thread to add to the thousands that are already out there about this.