Just thought I’d update with some info on the new light which turned up:
UniqueFire L2 Cree XPG-R5
http://www.dealextreme.com/details.dx/sku.33550
It’s definitely brighter than the TR-801 and a slighly larger, more blended spot. But it’s also more blue and not as large a spot as I was hoping for. The halo is smaller and brighter though which I think is good. On the TR-801 the halo is so much in contrast to the spot that it’s hard to see.
With the battery in it it’s 157g (compared to 115g for the TR-801), so it’s a little heavy on my currently slightly loose helmet. I’m sure it wouldn’t be a problem for someone with a good roclock type system.
I only had a quick play but so far it seems pretty even between small+light+bright enough – versus – bigger+heavier+brighter