Having not seen any reviews on the Cascade, I thought I would add some feedback.
The canoe comes in two versions, the Royalex which is currently advertised by We-no-nah, and the composite which they make only by special order.
The Royalex Cascade is an awesome river tripper. At 17'6" you have to work at tight turns, but she will run dry through large waves and has the capacity for a months worth of gear. We've used her on the Stikine as well as more local trips, and it's always a delight. The length gives her more speed than the shorter boats, and a fair amount of rocker still lets her turn.
The Cascade is good through class III. If you're running more technical water, I'd suggest a playboat. But if you want something that can be dropped off in the middle of the NorthWest Territories, and which you will paddle for a month as you make your way back to civilization, the Cascade is hard to beat.
The composite Cascade is a slightly different creature. She is longer at 17'10", lighter (about 60lbs in Kevlar) and my preferred version of the two. You can only get these by special order, though they do show up used from time to time.
The composite Cascade has a sharp entry under the waterline, so the boat is fast. Not Minnesota II fast, but she'll walk away from most boats. Above the waterline, the hull flares out like an aircraft carrier. We were in the Bowron Lake Circuit paddling one of those long lakes, when the wind hit and blew everyone to shore. We were still paddling in the 3' waves, and the Cascade was moving fast and throwing the waves away from the hull. The maneuverability of the composite version is about the same as Royalex, it's only the speed that's different.
The composite version also gets the sliding pedestal seats, so you can sit or kneel without the foot entrapment problems of a bench seat. And portaging 60lbs is nicer than 74lbs.