They really are very good and will provide a much better experience than the USB-Werk. They have a built-in supercapacitor that helps with the garmin 'shut down when you slow down' problem
Thanks I'm on a v tight budget, and cheapest I can find the Igaro D1 for is £159.99 on SJS.. It's really just to charge my phone while touring - I don't have a Garmin, sadly!
Just got a price match offer on the USB week for £58, so I think that's my best bet.
Thanks. I'd love one of those, but at £150, it costs more than my whole wheel... I think I'll go for USB Werk.