I guess their target audience isn't necessarily designers. To remove the current format would make it difficult to be compatible with their other services. It would be awesome if concepts was more user friendly.
Hey @dh, I know this is an old post, but I'm building an iPad app that should be what you're looking for: a simple, infinite canvas, sketching app, built for UX designers. If you'd like to try it out, sign up for the private beta at IdeateApp.com
I guess their target audience isn't necessarily designers. To remove the current format would make it difficult to be compatible with their other services. It would be awesome if concepts was more user friendly.