My CNA ROM isn't as stable as tdm's as of right now. I've just merged in the changes for MMS but camera isn't going to happen until Bob updates his sources for it.
As for differences, it's all about the frameworks. A few things I've noticed is:
You can center clock
Change up the reboot menu
Add navigation keys to the bottom, and change color
Change the number of apps being launched from the lockscreen, as well as the apps that are launched from lockscreen
Change wallpaper for lockscreen
Make a battery indicator on the statusbar
Change color for a lot of things
Option for statusbar transparency
Home, Menu, Back and Search icons in reboot menu
On/Off menu in statusbar
and a new option for build.prop edits such as:
Uncap 3g limits (awesome, IMO)
Change wifi interval
etc.
It's all based on personal preferances. I can tell you I've been running it for a while now, and I love it.
If you want camera, stick with CM9.
For more information, you may want to check out their website:
Codename Android
If you want to know where you can download it for the OV, You can get it here:
http://gannon5197.blogspot.com/2012/03/update-cna_17.html