Interesting thread,
about the bodyweight - we sail smaller 16ft boats, less sail area and narrower than Blade with less hull volume, basically looks like a 16ft scaled-down Tornado with old style mainsail (pinhead), only 12,45sqm sail area (main).
Wouter would say that a 90kg sailor would need a fuller-cut mainsail to give more drive, yet in anything over 12knots it is the heavy guys who sail fastest, granted they are the better of our class, but when sailing solo against the sloops Kevin recently won a 2 hour race by a large margin, he does have a bit more luff-curve which gives him the power he needs but that is very easy to acchieve provided your boat`s class-rules allow it, so confirm that before you choose boats.
If you have the choice to buy either boat, get the one which has the most number of good sailors in your area if you want to race, it`s that simple.

Steve