Even if I put aside my dislike of his writing, I can honestly say that he is not near the best Avengers writer of all time.
First of all, Stern, Englehart (both original and WCA versions), Busiek, Johns, Byrne, Thomas and Harras's runs are all far better IMO.
Second, while he did bring in a large number of new fans and has made the book a consistant top seller, he did that by ignoring everything that made the Avengers the Avengers. He has publicly stated that he doesn't like most of the characters that ARE the Avengers, and has either just ignored them or badly mangled their characters. What he created with New Avengers is not the same team as the previous Avengers. He missed the concept of the World's Mightiest Heroes gathering to fight threats that no one else could face. While the characters he has selected may be able to face these greater threats, they certainly have not been facing them (outside of SI, which really was neither just them, nor was it really as threatening as it was made out to be (but I attribute that to Bendis's writing)). The Avengers are supposed to be fighting world or universe class threats or at least country level threats (while occasionally facing city level threats or less), but Bendis's team rarely faces threats of that magnitude.
So, you may say that New Avengers is the best Avengers book ever, but you are missing the point that Bendis is not actually writing an Avengers book, he is just writing a book with the word Avengers on the cover.