I wholeheartedly agree with what Prmenrs post said. I also am a member of both NICU nursing organizations but not AWHONN (I feel AWHONN is more oriented towards the Labor & Delivery nurses). Anyway, both NICU nursing organizations are beneficial to us all and I want to do all I can to support NICU nursing progress... therefore I don't choose between NANN and ANN... I simply continue to be a member of each.
If I had more money to spend I'd join AWHONN but its a huge organization and I feel it's well supported by OB nurses enough that they don't need me right now. I do recognize the importance of keeping up with what's happening in the L&D areas since what happens before birth is incredibly important to the baby during and after birth.
I attended the ANN yearly conference last year in Las Vegas and had a wonderful time. I would have gone to the NANN one in San Diego but I just started a new job and couldn't ask for time off yet.
Maybe I'll reconsider joining AWHONN more seriously now that you've gotten me to thinking about it all....
Anyway, this is just my 2 cents.