Jonathan said, and I agree with this, that the bread's flavor was too simple, i.e. there was not any complexity to the flavor of the wheat. I think he wanted a slightly sweeter bread, which is understandable, since the only sugar in the sourdough was whatever the wheat had. Some more salt would also have help it, I think. Still, it was delicious, albeit it dense. It reminded me of the dark rye bread in Scandinavia (except this had little rye).
The density was another thing which Jonathan mentioned after trying it. It was definitely dense, but that, as mentioned earlier, was due to punching down the dough when forming the loaf.
I've got some more dough rising right now and the starter was a little wilder this time, but I'll hold off telling the secret ingredient until I've tried the bread.