I liked the idea of a 5-color Dragon very much from the beginning, especially because of the always mentioned Sacred Ground and the win condition Shivan Hellkite, which is the best available dealing with Platinum Angel.
Stephane, you asked us to ask you question about Dragon, so if and only if (even if it's debatable worse than your UB-build) you were to play 5c-Dragon, what changes would you make in comparison to Hale's List ?