Trust me, I've read the specs off the web site, just wondering if anyone has hands on experience they would like to relate.
I have it.
Actually, I've just bought one regular L2Dce, one L2D-Q5, one Q5 Christmas kit, plus 1 LODce and 2 LOD-Q4. So they've made some money off me.
I've done quite a bit of shifting around and testing since neither the Q5 heads, nor the Q4 performed as I expected as compared to the stock model, + another issue.
According to my tests, the output differences between the two battery types are small up to max level, (Panasonic CR123 vs GP ReCyKo NiMH), the lithium outperforming the AA 10% or so on high. The difference comes on turbo, where a fresh lithium gains another 60% from high, whereas the AA only gains some 15%. So a fresh lithium gives roughly 50% higher output on turbo vs. a decent NiMH, nicely matching Fenix-store claims. That is not likely to remain the case throughout the discharge cycle, of course. My results also matched their claim is that the fresh lithium should give the same output as the dual AA, L2D, body. It did.
I haven't gotten around to measuring battery lives for the different drive options, nor have I measured drive currents yet.
Hope this helped a bit.