Hi,
I did a comparison of ViewNX, Aperture and LR RAW processing before I chose Aperture to process my NEFs - I'd more or less decided that Aperture was going to be my DAM after trying LR and it, but wasn't sure about the quality of the processing.
I discovered that whilst Aperture didn't recognise the NEF secret sauce instructions that the camera embeds in NEFs and that ViewNX / C2NX recognise, the processing was better. By better I mean more latitude in recovering underexposure and blown highlights as well as much lower noise in high ISO shots (this really surprised me).
C2NX might be better than ViewNX though - not sure how they compare. Anyhow, I no longer use ViewNX for anything and don't miss it one bit. I was considering C2NX for editing, but after finding PSE6 on sale for $50 (woohoo), that became a non-issue!
If you have an Adobe-shaped brain, you might find LR works better for you. Enjoy the experimentation...
Regards,
Calx (away from the mac and away from home)