I have bought everything from DSLR's and high end glass to filters, flashes and batteries. Never a problem in many years of dealing with them. 10+ in my book.
I got my D70s from them, as a walk in. I have since bought a lot of accessories and other things from them. Everything was fine, good customer experience.
Have bought from both Adorama and B&H without out anything but the most nitpicky complaints. Not sure what to say about the warranty. Looking on their page the mention something called Sagemax warranty. I have Mack warranty on my cameras video and photo. Like having the extra warm fuzzy for the small price.
Just bought my D80 from B&H. $795 to the door (I think that is a fair price, body only). Had it in 3 days. I will definitely go with them again in the future.