Can anyone out there tell me?? on the canon 20D camera adding the Canon
Extender EF 2xII to a 70-200 2.8 IS USM lens degrades the quality of
the picture??. I know that I will give up a few F stops and certain
autofocus features do not work. But what I was wanting to know, if
there is anyone out there that has used both of these lens together and
do you have any sample pictures. I would be mostly using the combo for
wild life photography and occassional sports photography!!. I have
heard some sales reps in camera stores say " you need to buy another
lens". I wanted to find out if buying an extender is worth it???.
Collecting all the info I can, any resources shared is greatly
appreciated.

Max