I was asked for feedback of the NPE beta.
I don't really have any feedback, but since you asked...
I guessed the download URL (www.norton.com/npe_beta) before I was granted access to the beta board.
I ran NPE and noticed a new GUI and rootkit scan was not enabled by default. After the initial scan I enabled rootkit scan, restarted my machine and the scan completed.
No detections so can't comment on effectiveness or otherwise.
NPE is not a tool I would use often and not one I would recommend. It's all well and good to say you can undo any changes made by NPE but it's a bit late after critical Windows files have been removed resulting in a machine that no longer boots.