Thanks for all the great pics.  I ordered they space grey sport, and was thinking of getting a second band for variety.  
I really like the Milanese band — it's comfortable and easy to put on and adjust.  However, even though it doesn't look too bad with the grey case, it doesn't really match either.  I like the dark, satiny look of the grey case and the Milanese loop is bright and shiny.  
More than the look, I worry the hard steel might damage the softer aluminum case over time.  I think if I really had my heart set on the Milanese loop, I'd convince myself to spend the extra $200 and get the stainless steel Watch.  The ideal combo would be the non-existent space black Milanese loop with the matching space black steel case — perhaps this will be an option in future releases.
The leather loops all look great.  However, I have 185mm wrists and the large loop was a bit too big while the medium loop was difficult to get on.  I have to go back to the store and spend some more time trying them on to see if they would work for me. 
I would think it's just a matter of time before a Product Red band becomes available — that's bound to look nice with the space grey watches, too.