you can use any ATF fluid that you like, it just voids the warranty, assuming your transmission is still under warranty.
Nissan states they put "special" additives to protect the transmissions. Whether it's a gimmic or not, voiding the warranty is not a gimmic and is true. I might have heard of one transmission failure on the .org, but not even sure about that. And most are using Nissan Matic J or S.
You can use:
http://www.amsoil.com/catalog.aspx?code=ATFQT-EA
Which, specifically says it's compatible with Nissan Matic J. It's more expensive than Nissan Matic J or S, and most transmissions I know of haven't failed on it, so I don't see a valid reason to switch.
There are some that even don't recommend a "power" flush, where it can do more damage than good. The Nissan mechanics won't do it on CVT transmissions for sure, and only do a drain and fill (6 qts). They recommended I change the transmission fluid more often, but only do a drain and fill vs a full flush (12 qts). Said it was safer on the transmission.
Are you thinking of switching or just curious?