I bought 2 600EXII at two different times when they had sales on. Don't think I'd pay full price on it anymore. Came in generic packaging, but once out of box, there is no difference between them and a brand new one. They came with full warranty, too. Work just like brand new ones.
Bought an EF-S 10 -22 lens for my daughter, ordered on the Nov 9, and it came on Nov 10, Illinois to Virginia, can't be more pleased. Again totally generic packaging, double boxed. Initial shots were excellent. I may get one for myself to mount on my 7DII.
I'm now convinced that I'll buy this route. Taxes must be paid, either way, shipping usually not. I'm still ahead in a few ways. No pain.
As I said above, I've had good experiences. But I am curious. I have always been hesitant to buy a refurbished Speedlite. Lenses and bodies don't worry me but the element that flashes has got to have a finite lifespan. Anyone out there have any thoughts about refurbished flashes?