Back in the day, Canvas was a great program. I have ~15 years worth of scientific graphics in .cnv and .cvx formats, but no way to open them. I downloaded the demo and tried to open a few representative files. To my surprise, ~80% of them opened just fine. (One was really screwed up.) More interestingly, I was able to select everything in the Canvas file, copy it, then paste directly into a new Illustrator file. Not only did the transfer work, the images appear to be editable in Illustrator.
While there is no way that I am going back to Canvas (particularly after being burned so many times), I will probably buy Canvas Draw just for access to the dark past.