I didn't mention in my post about the new lens that what I had actually ordered was a 50mm f/1.7 lens. Somehow the person I bought it from sent me the wrong lens, a much more expensive lens. Alas, it had to go onto its rightful owner and I was sent the proper 50mm f/1.7.
So there's the bad news. The good news? The new lens is almost as good and it's hard to tell the photos apart.