I got mine and was planning a simple OOB and push through from the get go. I even cleared the bench when I had tracking numbers, cracked the box hours after it landed on my porch.
I've been waiting for a styrene Discovery since I made on out of card stock when I was 10 so I had no intention of getting bogged down in lighting or aftermarket stuff.
Then I looked a my references and decided I wanted to get the windscreen (?) right. In 2001, it reflects the curve and angle of the sphere itself, broken up into five panels, the outside two at an angle (apparently in 2010 it's squared off like the kit included piece). No big deal, I made a buck from the inside of the sphere and vacuformed a new one. Then I decided I needed to add the ridge above and below the window and thus opened the floodgates. I ended up with the Paragraphix cockpit that I'll use as a base for so scratch building, including sculpting either Poole in the walkway and Bowman at the right angle with clipboard or Poole in the command chair and have a very bright light as the pod bay door opens.
Looks like my quick, simple OOB will become a long, dragged out build.