I took my first roll with the fisheye today and was both surprised at how well it performed and how much more skill I really need to use it well. I read reviews that said this lens was soft (it is, at the corners, and expecting it not to be is silly) and a lot of people seem to dislike it. I think this has a more limited range than many lenses and needs to be used for special purposes not as a general lens. Right now, I think it's probably in the 8 range on a 1-10 scale, but I need to test it with about 100 more photos before I feel like I can write a competent review.
Here, however, are some early pics as samples.
I had to punch up the contrast because I scanned a print. HP5+ shot at 400 ISO.
So, yes, it warps the world a lot.
But as a portrait lens, this is actually a pretty good option for creative portraiture.
Up close, even at f11 the DoF is really limited, so don't expect this lens will be great for grand vistas and deep-field shots.
Portraits would be best served if the lens is not higher than the person, unless the goal is to make them look small with a huge head and super-tiny feet.
At four feet, there's some substantial distortion.