For what it's worth.
I have a 6' wide, 20.5" tubes prototype Spider. I purchased in the spring of 14.
I run it it with a 3 bay frame. Rower sits on a 65qt cooler, 2 20mm cans or water in the cockpit, and either a 26" square dry box or drop bag. Side rails for cans and misc. Beaver tail behind the rower when there is a passenger, and in front without a passenger. Weight distribution is important to keep the boat trim.
I have found the boat to be very stable and nimble. I have yet to overload it, you run out of places to put stuff. If you leave a couple of the heaviest luxuries at home it hardly has any draft at all.
It fishes two people and their multi day gear well.
I don't have enough miles as a paddle boat to have a firm opinion, though it's very promising what I have done.
I really don't have any complaints, it's been an awesome and fun boat.