In reply to EZ: I'm not quite sure I understand your second post re prices.
With reference to comparing the magicshine to the rxp and nao though, I agree with you that they're completely different machines. Like you say, the MS is probably a bit heavy for the likes of running.
It sounds like an awsome beast though, but it's definetly into the geeky/high powered mounted mountain bike category where as the Petzl's are in the all round use bracket. You could use the Nao for winter mountaineering, night running and mountain biking where as I think the MS would be overkill for the first two. The lumen geek in me would like to see one in action though, I wonder if you can get one of those battery pack harnesses you used to be able to get for the big silva halogen lights.
I'm not sure about Petzl's pricing, some of their prices make no sense. Part of me thinks Petzl aren't really sure where they fit in in terms of value torches, mid range and top end. Their lower end and high end torches are a bit of rip off, £45 for a tikka XP and £300+ for the ultra! They've even got a tikka xp package including the core rechargable battery which unbelievably clocks in at £85, which is totally insane.
The RXP is a great machine though as you say and if you can get it for £50 (making sure you get the newer version with the improved cable attachment) then I think that's reasonable value. Going by RRP though it's almost twice as much as the Silva trail runner and I'm not sure there enough difference in performance to justify that.
In terms of value for the Nao though I think they've got it spot on. Like you say, Petzl are good on the construction/quality side of things and if the variable lighting works well then £140 for a 355 lumen head torch is pretty good value, in the "all rounder" bracket anyway.
Ben