Received my TL 2-L today from BrightGuy (excellent price and service, BTW), and here are my initial impressions:
Form factor: Handsome overall, nice black finish. Fits well/feels good in the hand. The gradual incline from bezel to body is a plus---feels more natural, and doesn't "catch" in pocket.
Switch: Since I prefer the "underhand" way of holding a flashlight, this button switch is a nice change from the common "clickie" tail switch that is activated by holding the torch "tactical" style. Although lo-hi-off would have seemed more logical than the hi-lo-off switching order of the TL 2-L, it's easy and fast to toggle between the settings, so no big deal, especially after getting used to it a bit.
High beam: I was pleasantly surprised. Seemed to compare favorably overall to my Pelican M6 (108 lumens per BrightGuy)---maybe not quite the distance throw, but at moderate to longish distance, the TL 2-L had a much larger spot and overall illumination. Besides the nice spot, spill on high was very good---really lit the place up!
Low beam: I agree with DanM on this. Best described as a "mini-spot", with OK spill. I compared it tonight with my Inova X5T, and of course the Inova is the spill king. But the myopic range of the X5T bothers me some as I poke around outside in the dark, and the TL 2-L, in contrast, has quite a bit more forward projection (throw), giving more confidence as to what you're walking into. Haven't given the low beam a serious hiking-at-night test yet, but I'm cautiously optimistic it'll be up to the job. Ideally, I would have liked the low beam to be at ~35-40% of high beam (vs. 25% as designed), but Streamlight didn't ask my opinion.
Practicality/useability: High scores here. Frankly, for my purposes (general skulking about outdoors at night, both at home in the "exurbs" and at our 83 acre "ranchito", where I'd rather be most of the time, a 2-level light makes more sense than anything. I want to see where I'm stepping, but there is always some critter or something out on the periphery that I want to spot.
So, a 2-level is probably the ANSWER for me. I'm surprised that there aren't more decent ones on the market. I am tempted to try the SF L2, but a few things are momentarily holding me back: cost; only 15 lumens on low beam---can I walk my nighttime trail with that?; I don't understand how the tail switch works---for constant "on", can you twist the tail cap with one hand? I would appreciate any comments from L2 owners.
In any event, the TL 2-L gets high preliminary marks in my book---~B+ to A-. Dukester, if you're out there, I think you're gonna like traipsing over your acreage with this one!