After much research, I settled on the Scorpio. It has mostly met my requirements. Certainly getting it on edge is easy, and I can now practice turns without the need of a rudder. The tracking is somewhat light, with a tendency to wander, but that is the price of a quicker handling boat. A touch of skeg and it tracks straight and true.
Speaking of the skeg, I have mixed feelings about it. Having a skeg instead of a rudder has been an interesting educational process, adjusting the weathercocking with the adjustment slider. The design of the skeg (a rope skeg) is clever, and does eliminate jamming or kinking in the alternative wire cable skegs. And running aground with the skeg down is no worry.
However, the execution of this design leaves something to be desired. I got one of the original models where the skeg rope was actually a length of shock cord. When wet, this cord would lengthen, altering the adjustment of the skeg, and it would swell in diameter greatly increasing the friction of the adjuster. This became so bad that the device was almost useless when wet, only to correct when dry.
I was rather impressed with the solution P&H came up with. Any owners with the old cord can email P&H and request the skeg upgrade kit, which consists primarily of a thin, non-absorbent, ultra-low friction dyneema cord, and installation instructions. A tip for installation given by the MEC store was to use a section of fishing line to tie the new cord to, and feed it through the cord housing.
Tying the knot to secure the skeg adjuster is trickier than I hoped; I actually got it so tightly jammed that I couldn't undo it. However, once that was in place the skeg works exactly as intended, with no troubles.
Incidentally, Dyneema cord can be sourced in North America from arborist stores under the brand name "Fling-it". I tried this product as a substitute and it works well; knot positioning and untying is easier. Not quite as friction-free, but miles better than the original shock cord.
Another frustration is the knee/thigh braces. Although very comfortable, I found the bolts and brackets almost impossible to adjust. Fortunately, I like the stock position; excellent contact points.
The hatches are essentially dry, with the exception of the fourth hatch over the thighs. It leaks from the inside when water enters the cockpit during wet exits. Rolling the boat is easy.
Despite these hardware problems, I still love the performance of the boat. It handles much better than my old boat, and has allowed my skills to move forward. I wish P&H had got the skeg right from the beginning, but now I'm satisfied. I believe I'll be paddling the boat for the next five years before I go looking again for the next big thing.