Ok, im curious. If you could have an LED light, either 1 cr123 or 2 cr123, what would you want it to do?
What you state is actually pretty close to my idea of a perfect "do it all" general purpose light.
There are good reasons for every form-factor out there, from Photon-style keychain lights to HID lights that require a shoulder strap; but for a "do it all" light, the 2xCR123A / 18650 size is a good choice. (I know you specified 1xCR123A / 2xCR123A, but the size difference between 2xCR123A and 18650 is negligible, and the the latter has a real advantage in flexibility and runtime.)
It'll fit in a jacket pocket, or pants pocket in a pinch, or be unobtrusive on a belt; yet is capable of good runtime (decent size batteries), good throw (generous reflector), and good ergonomics (hand-filling size).
Variable output is a must; more specifically, a wide enough range of output to handle situations from arms-length at night without ruining night vision, to throwing illumination 100m into the woods. The usual two-levels (with a resistor wasting energy on low) won't cut it; fully-regulated, controlled-current, multi-level drivers have made it to the *** market (thanks, Fenix!), so the technology is there; there's no reason to settle for a single, or even dual, output level.
Speaking of throw, focusability would be a great feature. I have a few lights with ungodly throw, but the spot is so small that it's of very limited usefulness in the Real World. Sometimes you need to fill up a room, not project a tiny-but-bright spot.
All the manufacturers seem to be striving for the "perfect UI"; it's difficult to balance flexibility with user simplicity. But the most obvious need is one of the most neglected these days: momentary-on! It boggles my mind how few lights out there have a decent forward-clicky switch. Of course, a forward-clicky doesn't work easily with complex UIs, either...
As far as materials, titanium is exotic, strong and luxurious; but aluminum is still ideal for heat dissipation and light weight, and with a good HA-III finish, can still be tough and attractive.
The closest I've found yet to my ideal is the Dereelight CL-1H v2.0. The size is right, the ergonomics are good, the finish is excellence; the newest version sports a Cree Q5 emitter with three regulated output levels (about 1A current on High, for impressive performance), with a forward clicky; however, they gave up the focusing feature from the original 1.0 version, which I dearly miss. The original used a twistable ring near the head, SureFire U2-style to change levels, but only two levels.
So my dream light wold be something like a love-child of a Dereelight CL-1h and a SF U2: the momentary-on forward-clicky and superior output of the CL-1H v2, a couple more output level options like the U2, the U2's separate output level selector, the focusability of the CL-1H v1, the solid construction and HA-III finish of both.
Really, is that too much to ask for??
