Something perhaps worth remembering is that the heavier platform will in itself put more stress on itself than the lighter platform. So, if one understands that a thinner skin means you can't drag it up the giant emery board called the beach (but a lighter weight would remove less skin doing this) as much but in most other respects the lighter platform might out perform the heavier platform in strength tests.
I have an old school Hydra and a Taipan platform.
With the Hydra I have to drag it onto the beach to stabalise it. With the Taipan I can just lift it so it doesn't drag and settle it.
A platfrm is as strong as its weakest link. So, if the bolts holding the thing together are the same in light and heavy, the light boat is stronger as less weight = less strain on bolts.
One thing is very clear to me.. lighter = better sailing, feel and control. There is no reason to have a heavier car unless you want to smash it though a brick wall and I think the same applies to boats.

Take a Tiapan for a ride and you probably won't look back as while you might break it you will have had more fun doing so.