"Hand holdable"? I bet hand holding these babies gets old real quick Even if lighter than the previous generation, they're still heavy. I have the old 400/2.8 IS and it sees much less use than I'd like to because it's difficult to carry around (and transport on airplanes). Granted, it's a bit heavier than the newer ones, but still, unless you have an assistant carrying gear for you, don't count on taking the superteles too far from the car. That's why I'm seriously looking forward to a 400/5.6 IS, if it ever gets released.