I know everyone is tripping over each other to say how great it is that it runs on AA's, but bear in mind we do not know yet how it will perform on Alkalines. My guess is badly.
The difference in output between this and the SC600, as I feared, just does not seem great enough. You have a larger, heavier, uglier light for no good reason.
Sure you can buy Lithium primaries, but that will very soon cost much more than just buying an 18650 or two.
I like Zebralight, but I am sorry I just don't get this one.