I have the 14mm. sometimes I think its better than my canon 16-35/f2.8 II at 16mm.
I also just purchased the 12mm fisheye on sale. now i have 12mm & 14mm. Does anyone have experience with the two? Maybe some knowledge on how sharp the corners are on both at low light, landscape astrophotography. I haven't had time yet to test..maybe someone knows of a review.