I've had mine a over a month now and it has been great. As above they probably aren't 900 lumens but to be honest they seem as bright as all the Ayups/Exposure lights that my riding buddies use.
Totally agree with Dan : / I've had one of the Deal Extreme Magic Shine bike lights for about a month now and for the money it's amazing. No problems with proper night rides with this on your bars/helmet.
I rode home with it on tonight on my usual commute as my commute bike had a puncture and pedestrians and cars were looking at me as if they'd never seen a bike light that bright. The lower setting is brighter than any normal Halfords/Cat Eye commute light you can get.
Get the DealExtreme MagicShine one as posted above. I've bought one for night rides and it's an amazing piece of kit for the money. It's as bright as th Ayups/Hopes .etc that my riding buddies are using. Will be way more than you need for towpaths/commuting but the latest ones have 3 modes - full/mid/flash.
Have you tried emailing Howies to see if they have any floating around?
Failing that I have had a Vaude Bike Alpin Air 25 + 5 for about 2 years now and couldn't be happier with it. Has lots of reflective bits for commuting and expands with a extra 5 litres if needed. Not sure what size you are after but they make a lot of different sizes.
gregster 
