IMHO, 28 1.8 is a hidden gem. I think there are a couple reviews floating around that knock it for sharpness and CA, but I sincerely think they are blown out of proportion. My copy is sharper than the 50 1.4 with both at 1.8, sharper across the frame, AND has equal if not less CA. To me, CA is not a deal breaker anyways since it can easily be corrected in PP'ing.
On crop, 28mm is the way to go. For FF, it gets a bit more subjective in that it depends on what focal length you prefer. For me, I am finding that I wish I had 50mm on my FF because I'm having to get too close to my subjects, which is therefore introducing distortion.
, as an alternate way of maintaining communication with our members and sharing/discussing the hobby.
