Geoff, sorry for the blase reply, just I’ve posted the basic info time & time again on any number of those threads (as no one seems able to search) and could do with a personal closed post I could just point to & update ever more! 😉
But lots of those thread don’t only include recommendations for the MS/DX units, lots of other are discussed, so they are worth a butchers through them..
Off-hand from personal experience with the MS/Smudge’s light:
Smudge’s XM-L are fricken bright, loads more throw than the original P7 (not too hard as it was very floody) and more than the 4x XPG MJ872 (throw that is), but it is quite a specific tight spot which can get lost in open area. A great helmet light but still very usable on the bars. Don’t get put off by the report of the hot spot, the light is great but you need to understand it’s just not perfect, we’d be remiss in not mentioning it.
MJ872 – lots of floody light, lighting up everything for a good distance, not as bright anywhere as the XM-L centre spot but very very good. A great bar light, to give you lots of usable light everywhere.
The XM-L is available cheaper from DX than Smudge but you’d have to wait for delivery, the reflector looks very basic (more of a hotspot potential) and you don’t get the great service Mark supplies.
£89 on ebay for the MJ872 is cheaper than DX sell it, I can’t recommend buying it from them!