I'm not giving up my 300mm 2.8L ... I love it too much, but I have been holding off on getting a longer focal length supertele.....


If the new 600mmf/4 IIcomes in smaller, sharper with the new TC's and lighter than the current 500mmf/4 that would be verrrrry interrrresting!


For me that would be a nifty, hand-holdable combo.


I have almost pulled the trigger on a 500 f/4 several times....glad I waited now....will be curious to see the actual performance and street price and to see if version I prices go down.


I suspect the higher cost is because Canon is using more fluorite glass elements to lessen chromatic problems and enhance resolution, contrast and sharpness in order to keep up with sensor technology. These prices though will make a big dent in the price advantage that Canon has had over Nikon.