I decided to wear my Nano today just for the heck of it. Here's a quick pic:
Then I decided to take another pick with my MS Band just for comparisons sake and to try to get an idea of how the 42 mm watch would look on my wrist. Here is that pic:
The Band is about 50 mm long. The black part of the Nano's screen is about 37-38 mm top to bottom. So it looks like the Watch will be a little longer than the Nano and a little shorter than the band. I think it will be just about as big as I would want to get on my wrist. Looking forward to getting the real thing...
FYI - I'm left handed so the bands are on my right arm...