Thank you, that's super helpful and interesting. I'll be putting this together early next week - really looking forward to seeing this beam!Run it around 840ma, much more than that seems to actually reduce the output. I'm not sure if it's actually outputting less power or if the wavelength is increasing and making it appear dimmer but either way they seem to have a hard limit on brightness. Someone did a power test on either LPF or PhotonLexicon and reported the same, hard limit on output. Much less divergence, about half that of a P73 but larger beam waist at output, about double the cross section size. Less beam trash than a P73 as well. Definitely the nicest looking beam of the high power multimode 635's just would be nice if you could overdrive the crap out of it like the p73 and get big power.