Just received my 321 as well! It's absolutely beautiful and i really love it. Second Omega I own now, right after the green Seamaster 300m a few weeks ago.
But i've run into a little problem. I pressed the top pusher button for the first time to try out the Chronograph function right? And after using it, i realized that the top pusher was jutting out and uneven as compared to the bottom pusher!
I immediately brought it down to the Omega Boutique and they said it was better to send it in for servicing immediately, and would most probably have to send it back to Switzerland, because only they would know how to work on a 321.
Waited so long to receive it and now I have to part with it for months again.
How does this even happen? I don't think i did anything wrong. I just pressed the top pusher normally. Why would it come loose?