Same with me. I used an N9 for a few months after it was first released, but I went back to my N900 for good last month and haven't looked back.

The N9 is a beautifully designed device that "just works" as a phone. But using the N9 has also helped me come to realize that the majority of my time using a mobile is not actually spent on the phone. Thus, despite all of it's quirks (and some embarrassing letdowns in business situations), I still get more everyday utility from the N900 then I did with the N9.

That's just my opinion based on my use case. Like I said, the N9 is a beautiful and powerful device, I just didn't get as much out of it as I do with the N900.