50 1.8 Mk 1 vs Mk 2

Ok, I have the Mk 1 now; what should I expect different than just the metal mount?

Better/faster focusing? Better IQ?

so wait, you are getting rid of your MK1 for an MK II?

Mk I is better in most areas.

Better build.
Better hood mount system.
Better focus ring.
Better distance scale. (Mk II has none)

Same optics in both.

Mk I has Arc Form Drive AF motor. (slightly noisier)
Mk II has Micro Motor AF. (similar AF accuracy and speed but some disagree and favour either the Mk I or Mk II)

Sorry, I should clarify.

I had the Mark 2, sold it, and now have a Mark 1. I plan to keep the Mark 1 due to the better build quality for it will be my "kick-around" lens.

Msowsun, thanks for the details on the differences.