I've bought a bunch of stuff from Adorama over the years, both used and refurbished. The refurbished page is really hard to find so I keep it bookmarked - here's the link

The last used item I bought was a Canon 300mm f4L in EX-. Glass is pristine. Body has a lot of little scuffs and chips in the paints. Works great - I've had it for around a year and a half. I also bought a Canon 50mm in EX-. Again, pristine glass and scuffs on the body and works fine - had that one for around 3 years.

In refurb, I've bought Canon's 100mm f2.8 maco and 580EX flash. I've had the lens for almots a year and the flash longer than that with no problems with either.

I've also bought used from KEH - last was a Canon 2x TC in EX+. I'd have called it LN.

In general, I think Adorama's ratings are very fair in terms of glass but only fair to slightly optimistic in terms of cosmetics (but I still buy used from them) and KEH's tend to be very fair to pesimistic (as in, it'll be better than they say)