Just an update. I ordered the 100-400 and thought I'd share a little about the experience. The lens arrived within three days and is in pristine condition. I checked the date code and it was manufactured in March of this year.
I haven't had much of a chance to use it yet, but have been doing a few test shots. I'm blown away by the results. I've rented this lens before and was pleased, but I'd forgotten how much I liked it. (Although it is dang heavy.)
I think another person on this site once pointed out that they like refurbished lenses because they know they've been checked out and brought up to specs individually, while a new lens may get only a cursory once-over on the production line. I don't know if that is true or not, but it makes sense to me.
Bottom line: I've giving Canon's refurbished store a big thumbs up.
BTW, I bought a refurbished 430 EXII through Adorama last year and had much the same experience. It arrived in a Canon-branded box, had documentation it has been refurbished by Canon and was in absolutely perfect condition.
On another topic:
15% would be an even better bargain if Canon would not slap sales tax on the final invoice value... BH/ Adormama etc are cheaper cause they don't put sales tax on top when shipping to Indiana.
Canon has no choice but to charge sales taxes on their products. Don't blame them. It's the law. Amazon and other sellers can avoid charging sales taxes because they have no physical presence in your state. But, just so you are aware, you
probably owe the taxes anyway and while most states don't do a good job of auditing these purchases, that is changing.