I haven't purchased any used equipment there, but they are a reputable dealer with a return policy, and I've seen some good deals there. They can be a little brusque, but--Hey! dis is New Yawk!
I used their E-6 processing once and don't recommend it--dirty rollers.
I keep loosing ebay auctions for a 150mm Componon S. They have one of the best used enlarging sections I've seen; but still not what I'm looking for. But was considering buying one from them if one arises. And as well conc. B&H. Bought both used and new with great service. Hope Adorama's the same.
Might depend on what you want to buy. For new they're OK, but they gets lots of returns and they reship these as new. I once looked a new B&W filter that had greasy palm prints on it, for crying out loud. B&H consistantly rates the condition of their used equipment MUCH higher than an objective observer would. this is particularly the case with large format equipment. Things I've seen them rate at 8 and 1/2, I wouldn't have given a "4". misrepresentation, in my book.
there are many good, smaller dealers in the NYC area with large stocks of used, professional equipment, with a 15 day return policy. It's nice to deal with the same person on the phone each time you call. I'll give you some names, if you want.
Jerry Pournelle, the Byte columnist and SF writer once coined "Pournelle's Law" --- "Never buy a computer from someone you can't get at with a baseball bat." I think this also applies to camera equipment.
Just five minutes after ordering something from Adorama! LOL! But seriously folks, you have to give Adorama a call just to hear their phone voice speak spanish in a thick brooklyn accent! It is a hoot!
My vote for used equipment goes to KEH in Atlanta, they are extreamly picky in there rating system. I can buy things in "excelent" condition which is the lowest rating before their bargen catagory, and I would swear that it was brand new right out of the box. I have been most impressed with their products and service.
As for Adorama, I have bought used from them before and I will not do that again. They sold me a used Contax RTS that was rated 8+ a while back. When it got to me it was missing the battery cover. So I went and bought a battery cover from a local repairman, and the camera worked fine, for about a month. Then the whole thing died.
They wouldn't take it back, and so I ended up giving the thing away because it wasn't worth it to have it repaired. I felt cheated and Adoroama lost a customer.