Dark Dragon
Explorer
I tried this out once. At lower levels they are so far behind the curve as to be almost unplayable. The Level Adjustment is simply too high to seriously use a dragon PC in a balanced party. If you remove the Level Adjustment, then they become broken in the other direction.
Got the same impression. But sometimes, the situation perfectly fits for the dragon, e.g., nightly or darkness encounters, challenges that would involve climbing or crossing chasms, fight against melee types without bows. However, those seem to be rare unless the DM builds a story that relies partially on the dragon PC.
So far, I would play a dragon PC for the sake of role playing, and in retrospective, I had the most fun with my wyrmling (now juvenile) brass dragon PC. If you're more a player that wants to dish out damage or shine in magic accomplishments, your probably better off with a humanoid character.