Out of interest, how did your USM break? It's just I've been noticing mine starting to search a little more recently and was considering taking it in....
Whoa... 2 L-lenses wearing down? That I didn't expect.
But my Sigma 24-70 allready has been retrofitted with a whole new foucssing system too. Quality isn't what it was no more I guess...
As for the shots, you had the disadvantage of shooting in less light, so the sharpness isn't top noch in some, but the Gyrocopter is amazing! Great shot of an unusual birdie...
You simply can't compare a prosumer lense with an L-lense. I'm still baffled with the results of my Sigma 70-200 when it comes to colour and sharpness. Certainly when I compare it with my father's Tamron 18-250 mm.