Well Dave it would seem that your recommendation of a "New best light" has just provided yet another sale.
As said previously, I loaned my light to a friend who also tries to ride several evenings/nights a week during the winter months, and his exact words were when he returned it this morning were "phenomenal"
He now also has one on order.
http://www.ebay.co.uk/itm/161889168897?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
I'm actually putting the light back on my bike again to see if I can adjust to the whiter beam that it omits. As I actually prefer a more yellow beam, I might well try tinting the lens.
So there you have it a £9.49 light, running from a six cell cheapo Chinese battery pack that it is now on it's third season of use in the harshest of wet, cold winter conditions, neglected and stored in a basic pack, and still easily able to provide a full evenings worth of hassle free night riding, without coming close to showing signs of fading or causing issue.
It doesn't get any cheaper or efficient than that.