Hi guys, I'm wondering how much different are f1.4D AF and non-D AF version lenses compared each other on a DSLR camera? I know the non-D version is producted around 90s, it looks very old to me. So can I assume the build and proform quality of f1.4D is a lot better than the non-D version?? And how much a non-D version cost today?? Thanks!