Just a couple weeks ago I received my 600/4 IS II. I actually got it from Amazon.com! I pre-ordered at Amazon, B&H, Adorama, and Crutchfield and they delivered first (I was shocked too... though B&H probably would have delivered first had I not missed them opening pre-orders for a few days).

I've found the lens to be very hand-holdable for usable periods of time. I'd love to show you some real-world photos with it... but sadly all I've done with it so far is test it out. I've been so busy with other work that I haven't had the time for it's intended use: photographing birds from a blind. After seeing Bryan's ISO12233 charts with the 1.4x extender, I'm very glad I decided to wait and pick up the 600/4 II instead of the 800/5.6.

One problem with the 600/4 II is that it's still the same size as the original 600/4. This means traveling with the lens is a bit of a challenge. I originally was thinking I would eventually pick up a 500/4 II for trips. I'm planning on a trip to Glacier/Yellowstone next year, and hopefully many more to come after that. However it seems silly to own a 500mm and 600mm lens, so now I'm considering picking up the 200-400/4 1.4x when it becomes available. This seems like the perfect lens for trips because of it's slimmer profile. Other times, it would be a complement to the 600/4 II. I could see myself having both lenses in the blind, whereas it would seem silly to pack a 500 and 600. I don't want to hijack your thread, but if anyone has any thoughts about the 500/4 II vs 200-400/4 1.4x I'd be interested in hearing them, and perhaps so would John.

I saw this image some time ago on Dan Carr's Blog (dancarrphotography.com) comparing the sizes of Canon's new super telephoto lenses. Some food for thought.