TBH i didn't use it much...
It was mainly for airshows and motorsport stuff that i bought it. I've only been to 1 airshow in 2 years (so that one is out), and i've been to quite a few motorsport events now so a nice little chat with the marshalls generally works wonders.
It can also be used for nature photography (but i don't do much of that at all. In fact i'd say i've taken no animal / bird photos in over 2 years!).
If i told you that it was on the camera twice (maybe 3 times max) since i got it about 2 years ago and it cost me about £700 would it tempt you?
Link to the lens