After some deliberation (there's a thread I started somewhere) I decided for once to listen to the majority of the advice on here and plump for the X1 & X2 combination of the Gloworm lights with the quick release system.
First off let me comment on the customer service from CRGMoto . It's not often that you get someone who genuinely believes in a product and also wants to go that extra mile to make sure you get the most out of it but that's exactly what you get with these lights. Next day delivery, phone calls off the back of e-mails, spares sent out without a quibble, complimentary spares sent to help with fitting etc etc etc.
On to the lights. I was out with 6 other riders who had a whole array of different lights and from the off it was abundantly clear that I had the brightest light in the X1 and the light with the biggest wash in the X2.
The X1 is really bright, brighter than the X2 in fact but the X2 is what creates the big wash and the X1 creates the bright spot.
The lights themselves are minute. The X1 is the diameter of a 10p and the X2 the diameter of two 20p's side by side, and both are no more than 30mm long so when you fit them to your bike and helmet they are light and discreet. With the quick release you can cantilever the X2 over your head set and still leave room for a Garmin strapped to the stem ! Of course you do have to strap the batteries to your helmet and bike and TBH I would prefer not to but once I found the most secure place to put them it was a case of fit and forget(ish) - I still found myself constantly checking the straps to make sure they weren't falling off but that will go with time I suppose.
Battery life was great too. Because you very rarely need the brightest setting (I found the lowest setting on the X1 & the middle setting on the X2 was more than adequate for the blackness of the Peaks) then after a 2 hour ride both batteries were still at 80% (nice little LED indicators on the batteries which provide a funky green glow around your bike).
Finally, I can't fault the quality. Everything is put together well, and feels solid and there are some nice touches, like the remote switches for the light settings.
Overall very impressed and to boot I saved £200 over the equivalent Exposure lights. Definitely worth considering for anyone in the market.