The interface on the EX10 is good, but NiteFlux made it better, not by making it more complex, but by fixing its faults. On top of that, for the guy who wants to customize his light, they give you the programmability that lets you make it as fancy or even more simple than the compact user interface (You can actually have a one mode, fixed output level light if that's all you want)
It is hard to recall another light with so much hype before its release and so many preorders than with the D10/EX10.. After its release, anybody complaining about the double presses for ramping, stiff or erratic switching, or the user mode memory getting lost after shortcut high and low, often got shot down as a troll or an idiot that didn't know what he was doing. The honeymoon with Ex10 is over for some people, and for those people, the LF3XT is a light worth considering.
I, too, like my EX10 even with its faults. I just like the LF3XT more.
It wouldn't have been enough for me had LiteFlux fixed the few quirks in the EX10 interface, or switching and just given me that. But what really sold me was the beautiful LiteFlux beam with no Q5 artifacts! IMO, the EX10 even with the GD plus emitter can't come close as far as beam quality. While I grant you that design of the interface makes or breaks a light, the quality of the light output itself is nearly as important. After all, what are you pushing the button for if it isn't to see pleasing light? When you have both, a great interface and a beautiful beam like you do with the LF3XT, you have a winner!