It's got a bit of that mustache distortion, but it really is an easy lens to use. I've used it shooting weddings on 1Dx's and 5D3's and it was just euphoria compared to the olde 24-70, I'm sure it performs great on film too, uber contrasty.

Check out the 40mm pancake too, I just got a like new Elan 7NE for $25 and i'm planning on using that lens with it since it's about the size of a body cap. So far it seems quite a bit better than the 50mm f/1.8 at equivalent apertures.