A:
Just bought a "new" D10. The hull is different from the FS10 currently offered. The version of the D10 I have is a "tunnel hull" design that is also found with the FS12 and the lower cost A10. It is best to see them in person!
The FS10 hull had lots of warping in the 3 showroom examples I looked at. Some of the D10s also had bulges but not as bad as the FS10.
The D10 and the FS12's "Tunnel Hull" seems a little more rigid due to the engineering geometry of the double arches (tunnel hull) on ether side of the keel line on the bottom of the plastic yak. The thickness of the plastic seems the same just a difference in design. I wanted to get the FS10 but $100 difference and the hull made me choose the D10 design. QA/QC your yak before you take it home!
I will be testing mine out on the Current River next week downstream of Montauk State Park in Missouri.
Hope this helps.