I do the exact same thing! That grey color is really gorgeous, I think it's the most beautiful Model S color, hands down, no contest.
I, however, went with the blue...For me, the interior color was more important, and the only color I liked I was the grey leather...And I don't just like it, I LOVE it, especially with the matte Obeche, it is so Zen. And, I just couldn't bring myself to get a car that was grey inside and out...And I really like the blue exterior/grey interior combination, so I don't really regret my decision...But man, I can really appreciate the beauty of the grey exterior.