I had the space grey for 13 days and even I couldn't stop giving it second looks lol. Wasn't enough power for me because i started using Xcode just recently and wanted to be future proof but I honestly wish I could've kept it as it was easily the most beautiful, portable, sexiest machine Ive ever used and I almost couldn't exchange it because of how amazing it was.
That said, I would go with your original gut feeling. Its usually what you'll be more satisfied with. (At least in recent history thats what I've experienced)
Goodluck!! You'll absolutely love either one anyways!