I've found that many sharpness complaints against the 7D come from the fact that since it's an 18mp crop camera it will mercilessly amplify every problem that might have occured when taking the shot. Such as atmosphere, motion blur, missed focus (whether it's user error or AF error etc.). So when people look at the 100% crops they are disappointed.
I've shot birds in flight with my 7D and was generally happy with the results. Still if I had a nice L tele prime, my pics would be much better. It's not the camera or the sensor that's soft, it's the other things. When someone uses a 30D, or XT with their 8mp sensor, these tiny flaws of the picture are not as much visible as on an 18mp image. They are there but not as visible, giving you a "it's much sharper than the 7D" impression.
Now you may ask then what's the point of the 18mp? Well, what's the point of a 190 mph Porsche when you can only drive 70-80 mph max on public roads... The 7D, when the lens, the conditions and everything is good is capable of very sharp 100% crops.
Sorry, I kinda got off topic here. but anyway, here is the 7D 100% crops thread with a lot of great shots that look sharp even at 100%
https://photography-on-the.net/forum/showthread.php?t=799284