A few downsides:
The colour doesn't match the space grey, which seemed like a no-brainer to me.
It puts extra lugs on the side of the Watch which I don't find attractive.
No idea if mine has been dispatched as the Sister has ordered it for my Birthday but assume the lot will of been sent from China in one order which they've just received.
There is some nice straps out there but I don't think a lot of them would look good with the Space Grey Sport. I'm tempted to get a silver coloured sport and change bands. Just don't know what to do. Aargh!