I just got mine recently. I don't have measuring equipment for lumen ouput or anything like that, but I'm happy to share my impressions.
First it is a bit less powerful to the eye than the L1D CE (on highest output). We got a report of a manufacturer's claimed output of about 70 lumens for the F1 (this info. from MattK of battery junction), whereas the L1D claims a 90 lumen highest output.
Then, it is also quite a bit floodier. The beam is also smoother and rounder more naturally, as it is driven by the SSC P4 and not the CREE XR-E.
It seems very high quality construction, the threads are impressively smooth.
It is a very pretty light, and can use all kinds of batteries, so it is very versatile. It is designed to be simpler and has one mode of output, by twisting the head. It can stand up as a candle. It is mainly intended for indoors use, not really the light you'd take for a forest hike (though it would probably be OK inside a tent!).
My reading is that it is designed a lot with style in mind, for those consumers who like to show something with a bit of flash in it, so it keeps the technical complications at a minimum. It doesn't even have any springs inside, that's how high quality it is.
Oh, and last, but not least, the beam itself (tint, shape) is the most beautiful I have EVER seen. Sometimes I find myself just looking at the beam itself, instead of the thing that I started pointing the flashlight to!