Alrighty then... someone here turned on the gene I'd taken so much effort to suppress -- "Hi, I'm Russ and I'm a flashaholic"
So the Thrunite TN-12 mentioned upthread arrived today and all 840 lumens will be going with when the dog gets walked tomorrow morning. I really need to see what that light does outside when it's dark. It is the neutral white version and appears to be a straight white tint. Cool white will get you the highest lumen numbers but lumens take a back seat to color imo, Warm white is too yellow and cool white is too blue, neutral is the way to go. YMMV.
A couple 18650 batteries came with it and they will not fit in the Surefire 6P -- end of discussion, not going to happen.
LesSnyder's comments regarding the Solarforce L2M are very compelling though. Parts seem to be compatible with Surefire except that the tube will accept 18650 batteries. I'd like to hear more on Solarforce wrt compatibility and modularity with Surefire.