Hi David,
Welcome to the forums. I use the 7D and 100-400 L combo. I agree it works really well. Sometimes the AF isn't as fast as I would like, but it is still much faster than my other telephoto lens (an old 75-300).
A few recent pics from the combination:
http://farm8.staticflickr.com/7119/7...c31fd563_b.jpg
Loon-7326 by kayaker72, on Flickr
http://farm8.staticflickr.com/7116/7...86c6e054_b.jpg
HB-7412 by kayaker72, on Flickr
http://farm9.staticflickr.com/8303/8...922489ef_b.jpg
small-8036 by kayaker72, on Flickr
Thanks,
Brant

