Well I'm mightly impressed with the Canon 2x extender especially when connected to the Canon70-200 f/2.8L.
I have what I think are some super shots with this combo.
However the quality of this lens combo was brough home to me a few days ago. I saw this high flying airliner Lufthansa 747 over flying us at 35,000-40,000 ft. I liked the way the sun was illuminating this airplane so i fired of a couple of shots.
Harry
http://i79.photobucket.com/albums/j1.../HighFlier.jpg
The next is just a crop of the first
http://i79.photobucket.com/albums/j1...fthansa747.jpg