I have found the S&G Night Heron to be a fun kayak to paddle. I am 6' 160 lbs. and really like the fit and handleing characteristics. The initial stability is excellent and the secondary is okay. For my weight I found the kayak did not track as well as I like and it has a tendancy to weathercock. I tried adding a little bit to the stern keel and found that it stiffened the tracking but I lost most of the manuverability that I liked. I returned the stern keel back to it's original shape and added a keel line skeg (1"x18") to the hull under the rear bulkhead area. I found this to work much better. The kayak now has very little weathercocking, tracks nicely and is still very manuverable and responsive to paddle strokes. I think the original design would handle great without any add on's for a heavier person.
I built mine from plans and eveything went together very well. The low rear combing allows for easy leanback rolls. The kayak is very fast. It's nice to be able to rest a little when paddleing with other people. It is a beautiful kayak that keeps turning heads. Many builders of other wood kayaks are really impressed with the curves and lines.