Hi Paul,
For me (an example), I had a computer report it had the Bloodhound Exploit 167 (I think). I ran a full scan, it found more files and the computer would then blue screen when you rebooted. Had to blow that computer away and reimage. One week later, same threat hit a different computer in a different location. Ran a full scan, nothing else found. I should note that both times Symantec deleted the infection via auto protect. That threat is living somewhere in my network or these two computer hit the same exact website and got infected. I'm holding my breath that I'll see another computer get infected this Sunday.
That is why New Risk Found is not useful to me plus the fact that you have to open the MHT attachment on my Treo that does not naitively support that attachment. Now, if that event produced a plain text report, I would not mind it. Don't get me wrong, I have both notifications enabled, but I don't pay attention to the New Risk Found as much. This works well for me and for others that have larger environment would benefit more from it than me.