There's a good review here, with a description of how it works and some test shots. I second their opinion that the sharpness in the center part of the picture is quite good at f5.6 and f8, but it is of course not even close to a good normal lens. Depending on what camera you use it can also be tricky to focus, so sharpness is a bit hit-and-miss. If you use the larger apertures (f/4 and f/2.8) the image is not really that sharp anywhere. Some call that "artistic" or "impressionistic".
The lensbaby has a different look to it, that's for sure. Like a Holga the lensbaby brings something different to the table. The shot that someone worked up on PS, looks like it was done in PS. Nothing wrong with that, but its not the same as using a semi crummy lens with rubber washers as aperture rings mounted on a rubbery tube. The Holga/Lensbaby adds spontaneity to the shoot, you aren't exactly sure what you'll get. And often that makes all the difference.
It's very interesting to see the emotions this thing stirs up in various discussion groups. Some people have been outright rude, expressing their "amazement" at anyone buying this product and what a waste of money it is. Maybe that's just to be expected as most people, me included, are so caught up in pixel perfect sharpness and high tech. To me this lens is a bit of an eye-opener in terms of the difference between the technical and artistic aspects of photography. Even my first few attempts have more emotional content than most of my existing pictures that are more clinical. It gets me thinking outside my old comfortable box. If I can find a way of transferring some of these new thoughts into my work with normal lenses and develop a more artistic eye I will have won much more than the cost of the Lensbaby.
Just realized this thread has been moved to "Forum & miscellaneous". Are the moderators saying this is not a product that can be discussed in the forum for Canon compatible gear?