I agree with the positive comments about being sturdy, roomy, and a simple paddling solution. Regarding the weird tracking, it does have a tendency to peel off the to the left or right when you get far enough past the mid line. If straight ahead is 12:00, then it seems that the "peel off" happens at about 1:30 and 11:30, to either side. I wondered whether this was an intention hull design for maneuvering on rivers. It tracks fine, as long as you don't stray too far to either side.
Giving this feature the benefit of the doubt, it's of questionable use on lake, where straight tracking is preferred. I use a 17+ foot sea kayak, so my prejudice is for good tracking, but the Sunapee is a pretty rugged water toy for the money.