I ordered the 42mm aluminum sport right when preorders opened and received it on launch day. My thinking was that it was the first gen, I might as well get the cheapest version.
About 5 days later, I realized I was afraid of rubbing the watch against anything for fear that the screen would scratch. I also realized that stylistically, my instincts about preferring the aluminum were wrong and that I should have gone for the stainless steel.
That day, I placed an order for the 42mm stainless steel. The 6th day, the watch was on Craigslist and that night I sold it. I made enough profit on that that I'm getting the SS for $60 more than I paid for the Sport, making it a no brainier.
I know many people are incredibly happy with the Sport, and that's awesome. I realized after a few days that I should not have cheaped out, and am anxiously awaiting my SS Apple Watch.
I went through that exact process. I thought the Sport would be perfect for a first gen device. But I got too paranoid about scratches and dings. Now I have the SS.