I took that Savage River Shenandoah prototype canoe out on Atsion Lake a couple of times, once with the gunnels pulled in and the keel line flattened out and once with the gunnels pushed out and 3-4 cm (+/- 1.5 in.) of rocker added. Here are my impressions...
It's an interesting canoe because it's short at 14 feet, with a rounded-V hull, fairly sharp ends, with plenty of mid-section volume. At my weight (<150 lbs) it's wider and has more volume than I prefer for everyday paddling but I could see its potential for tripping, or as a versatile day tripper for larger paddlers. Initial stability was fine (though may seem a bit tender for lighter paddlers) but locked in quickly when leaned and was dynamically stable while paddling.
With the gunnels tucked in, it has a profile that lets you comfortably sit-and-switch with a bent-shaft paddle and for a short canoe it tracks well and goes right along without working too hard. It tracks much better and is faster than my Northstar Firebird but it's not a cruiser and needed more energy to keep it up to speed compared to longer, sleeker designs, such as a GRB Classic 14' 8" or Savage River's Blackwater 15. The tucked in Shenandoah would turn with some heel (axle or post) but I wouldn't call it nimble; still, I thought it turned better than a typical cruiser, perhaps because of decreased length.
With the gunnels pulled out and some rocker added, the canoe became much more responsive to axles, posts, and wedges, especially while kneeling. It's not as nimble as the sport canoes I've paddled but it did turn well enough. I thought the sliding seat system worked OK for kneeling as long as you're sitting at the forward end of the pedestal. A sliding bench seat might be perfect for the rockered Shenandoah, even better if you could integrate the comfortable bucket seat. I did notice that with the rockered profile there was more effort needed to get the canoe up to speed and keep it there; the flattend Shenandoah was noticeably better at cruising.
It was interesting (and surprising) to see how much different the same canoe performed with a change in gunnel width and keel line profile. At my weight the Shenandoah won't replace other canoes I paddle, but if I was going to bring a big dog along for the day or go on a multi-day trip it might be a fun canoe to own, especially if the adjustable rocker was integral to the canoe.