Upload & Sell: Off
I have been a customer of all three, along with Hunt's and have been happily served by all three. I do most of my shopping at B&H, and realize that "free" shipping means there will be a small delay. If I order on a Monday a.m. I can count on receiving my product by Friday at the latest with free shipping. Since I work all week and rarely shoot mid-week, this suits me fine. Returns are handled as best as I could expect. I ordered an item just before Passover this year and needed to return it. I waited until they re-opened and, despite the overwhelming return pile they must have faced, received a credit within two days.
I hate returning items to any of these stores because I know its costly to them to re-stock. However, lacking a local store, I have no other way to examine the differences between Domke bags than to guess as to which one I want and wait to see if its right when it arrives. That being said, I will always support a local store (30 mi. away) if possible first, and their prices are within reason. I will NEVER go there and use them as a showroom.
B&H and Adorama have wonderful showrooms when you're in NYC, and I rather support a photographic specialty store than a general, non-bricks and mortar store like Amazon. It costs money to maintain a store and employees in NYC and I appreciate that. While competitive prices are important to me like everyone else, so is support for real photo retailers - not just a general merchandiser. At least when I call with a question (or visit NYC now and then), I know someone knowledgable about photography will be there to help me.