That is a fantastic subject and shot.
Bottom line is (my impression) that placing aside all of the 7d's pro qualities as far as AF, body, etc. from a pure IQ point of view - I saw no large advantage - and even seem to feel a certain annoying softness in the images.
Agreed - from a pure IQ standpoint, the 7D has basically no advantage over the 550D. The softness probably results from two factors - one may be the NR settings, more NR means softer images. The second is that the 7D apparently has a slightly stronger AA filter than the newer cameras with the same sensor, and as a result, 7D images require a bit more sharpening in post.