Nice find on the FWAA. One thing worth knowing if you haven't used it yet: it runs on either a 14500 li-ion or a plain AA. On a 14500 you get the full turbo (and it heats up fast); on NiMH or alkaline AA it's much dimmer.
If you do run AAs, NiMH (Eneloop-type) is the better pick than alkaline: it holds up much better under high drain, and you don't risk a leaking alkaline inside a titanium light you want to keep.