First I have to say what a wonderful collection of photo shots you guys achieve
My 5dII has only been used for macro work, and I still have not managed that 'wow' shot, but as a tool it does give some great detail for macro work.
This is a bee in flight.
EOS 5D Mark II2630 by BasAndrews, on Flickr
And one of my favourite hoverflies
IMAGE LINK: http://www.flickr.com/photos/basandrews/9099183879/
EOS 5D Mark II1936 by BasAndrews, on Flickr