I paddled a Nahanni for about a week. The boat I used had all wood trim with a two tone paint job, and it was quite a head turner.
On the water the Nahanni is a rocket. Definitely faster then some tripping canoes a foot longer. It was also possible to turn it, although I would say tracking was this boats strong point. Paddled tandem, it's initial stability can make it feel tippy at first, but I found the feeling to be short lived. Take solace in the fact that you're probably not going for a swim, as it's secondary stability is very good. I was able to paddle (solo) with the gunnel skimming the water, And could easily dip it under the water and still pull back up.
Paddled solo, the Nahanni performed nicely. The canoe I was using had a kneeling thwart and pads, which were very comfortable. The boat retained the same characteristics as when paddled tandem, and with a little bit of a heel, becomes more maneuverable. It's not a pure sit and switch solo, so you do need to reach a bit on your stoke, and outside of leaning it way over, you won't get a perfectly vertical paddle. But you can't very well fit two people in a Prism, and as a combo tandem/solo flatwater boat the Nahanni seems like a strong option.
Rating: 9/10 - because my girlfriend says it's real pretty