My main concern about the D10 is the variable output. I would like to use the low and medium power the most, but does it take a long time to switch from low to medium as opposed to clicking the switch on the Fenix?
Just want to mention that the Jetbeam IBS user interface is the best of both worlds. You get to set 3 unique light levels, and you can select between the three with a quick tap of the switch. You set the default level the light always comes on in, and you can set two additional levels.
I have the Jet II IBS and love it. I have mine configured to wake up in the lowest mode. A quick tap on the switch puts it into a low-medium level that I use the most. Another quick tap and i get full power.
Unfortunately, the Jet II IBS is too bulky for EDC in a pocket.:sigh:
The light I carry in my pocket is my Nitecore EX10DG. It's user interface is not quite as good as the Jet IBS, but it's a close second. Plus it's smaller and it tailstands nicely. The Jet can't tailstand.
Lowest mode is about the same between the EX10DG and the Jet II IBS. The Jet is just a bit brighter.
Highest mode, the Jet stomps the EX10. The Jet is brighter and has a much longer throw.
If I had to chose one for EDC, it would be the EX10GD. I like it so much, I'll be getting the EX20, dual CR123 version when it comes out and the D20, dual AA light when it comes out.
If Jet comes out with a slimmer head light running IBS with the ability to tailstand, they could be a fierce competitior to Nitecore for ECD use.