Ok, another essay on this subject and all in my 'hubble' opinion of course, others may disagree:
I have one of Smudges XM-L, and it very bright, much brighter than the P7's and the throw is damned good. The 'issue' to be-aware of, is the intense hot spot negates the rest of the output. Though I'm using mine with my Trout mini to great effect, though I believe it would be a better helmet light than bar mounted one - I prefer the lower profile of the mini on my helmet.
The lad I rode with last night uses one as his only light, and keep's up fine.. but did mention about getting a 2nd light (maybe because we came across another group all using 2 lights).
Smudge sold me the head unit as I already had a battery, but obviously that depends on him having sold off a 2nd battery to some-one else..
Dealextreme do sell them cheaper (though report suggest they're a very very cheap build), but most seemingly have a smooth reflector which doesn't help the hotspot (awaiting results on another thread about replacing the front lense to defuse the beam), the one that has the similar type of reflector to Smudges is also getting very near to his prices & is ‘only’ 3 mode, a pet hate of mine (you don’t need high for road/canal work or it dazzles car drivers, and the low is too low..)
Another m8 is waiting for one of these 1600 lumen XGP LED unit to be delivered (10 working days can be a very frustrating 2 weeks!). Which I reckon will be as very similar output to my Mini, and also have lots of floody light... and this is cheaper than you find them on the dealextreme site.
PS: if you want to borrow a old magicshine P7 head unit (battery last an hour if that) in the mean time, I’ve got one doing nothing since buying the XM-L..