Gosh. For years I felt privileged as a Canon user for having the very lightweight 400 f/5.6L as a "gateway lens" to bird photography - and then the new 100-400 f/4-5.6L. Smug no longer! Have fun, Nikonistas, this looks great! P.S., having gotten used to "no image stabilization" in the 1.2 kg 400 f/5.6L, I still love it to bits, in good light. It's the only non-mirror 400mm lens that I ever expect to shoot one-handed (admittedly, near-zenith).