Here's the follow-up: everything worked fantastic. I regret not taking the 1.4x TC out of the "picture" during a few periods, but I'm still super-happy with what I/we got regardless. My wife liked the 100-400 (funny how losing 120 pounds makes someone more willing to carry heavier lenses...), so I may have bought the 70-300L "in error" (and may now need to buy a second 100-400). Anyhow, here's a link to the landing page for the cruise, which in turn has a link to our Flickr gallery for the cruise along with an index of what's what: http://photos.templin.org/cruises/alaska/rt3.html