~ I use view NX to convert NEF 14-bit lossless compressed files and do some minor editing eg. sharpening, contrast, saturation etc. Since viewnx is basically a simplified version of NX2, the performance of these 2 products should be similar.
Here's my thoughts.
It's slow, even on my 3.6ghz quad core (QX6850 (old school
)) and 4gb of low latency, high bandwitdh RAM. It takes a full ~5sec to change the value of the white balance or to change the value of sharpening. Worse still, it crashes after 30minutes of editing on multiple photos. Totally unreliable.