That said, I love my LensBaby on my Nikon F - great fun!
And I love my Spiratone Portragon. I have a long-standing plan to mount the lens from an Empire Baby in a Nikon body cap. Part of the Empire Baby's charm is from the curved film plane giving edge to edge sharpness (a relative term) in the horizontal direction and a terrific edge blur in the vertical direction. Rounding the film gate with a file isn't something I really want to do to a Nikon.