Congrats on your new phone. I bought one last week and the Apple salesperson told me it should have WatchOS2 on it already, but it didn't. My first attempt to install it didn't go well. I had picked the option to automatically load all apps when I setup the phone, and I started getting errors from the update saying there wasn't enough space. I started deleting things, not realizing there was plenty of space. It kept failing, so I just wiped it out and started over, and selected the option to not install any apps during setup.
So take 2... started it around 6pm. At 1am, it said it still had 3 hours left and was still downloading. I went to bed. Woke up the next morning and had the prompt on the watch to install it. That started the rest of the verifying and installing that took another hour. Not counting its wait time while I was sleeping, I would estimate it took 10 hours to install on the second try. I have 60mbps internet downstream bandwidth. Can't imagine why it took so long, but that was one week ago.
Since then, I have thoroughly enjoyed the watch and worked it into my daily workflow well. Its a keeper. Truth told, I'm returning the SG one I bought and getting a used SS in the mail that I bought on eBay.
One question I have for you... what attracted you to the black SS? To me, it looks so much like the SG which cost a lot less.