I've owned both the Cartens Canvasback and the Bluebill, and for my type of hunting the Canvasback is far superior to the Bluebill. The major prob with the Bluebill is the built-in middle seat, which makes using the boat as a layout almost impossible. Also, the overall design of the Bluebill is very similar to the ubiquitous 12-ft aluminum v-bows that are found in half of the backyards in America, so if you like that design save a bunch of money and just buy an aluminum.
Tha Canvasback is a great boat. Although not perfect, I think it's one of the most versatile small boats on the market today. I bought my first one 6 years ago and have since added another because I liked the first one so much (it's nice to have a backup). The only thing I would change if I could would be to make it at leat 6 inches wider, but otherwise it's a great boat for my style of hunting. I use it a marsh layout, and it hauls a tremendous load. I loaded over 100 dekes, including a dozen Bigfoot floaters, into mine most of the season and never had a problem. Very stable for a relatively narrow boat.
Hides almost as well as a Four-Rivers or Momarsh, but handles rough water MUCH better than either of those boats, and hauls a lot more as well. I have had mallards land within feet of my Can on many occasions.
I used a 6.5hp Beavertail initially but wasn't happy with the performance so I replaced it with a 9.9Johnson and it performs perfectly with it. It's only rated for a 6.5hp, but the 9.9 is a perfect match.
I painted my second Canvasback in open-water grey for use as an open-water layout. Works OK, but not as well as a true open-water layout. However, the higher freeboard makes it much safer than a Four-Rivers or Momarsh on the big water, and it will haul several dozen diver dekes without a problem.
In my opinion the advantages of the Canvasback would be severly limited if you wanted to use it as a two-man boat. It's big enough to carry two, just not the best design. If you want a party barge get a bigger boat. Best option is to make your buddy buy his own.
Overall a very good boat that will hide well in minimal cover but haul a lot of gear and get you home safely in fairly rough conditions.