I only have experience with the JilLite, two separate units, but I'd really enjoy doing a comparison if anyone owns a Microfire III that they'd be willing to share for an evaluation.
Owning a number of of lights and brands has allowed me to make some general observations about the different brands and I must say that the JilLite is one of the most impressive lights that I own. For one it has a Polarion reflector that is extraordinarily precise. One you collimate the beam the hot spot is like a pinpoint and the lux numbers are through the roof. Second, the machining quality is surpassed by no light that I've ever owned or held. It's literally flawless in that regard. At lastly it does have a 4 cell carrier which provides more capacity than the microfire and overall the JilLite is still a good amount smaller. If nothing has changed, it's still the smallest 10W HID in existence which is kind of neat.
There are many threads about the EZNite but here is the most recent thread that I posted on it:
http://www.candlepowerforums.com/vb/showthread.php?t=210824