dyee said:
Am I missing anything with not having a small light (single cr123 or less)? Whenever I look for a light I seem to want a single cell light but always seem to get a 2 or more cell sized light, with the features I want. Do you see any advantage of a single cell vs a 2 cell light? The only thing I can think of is they are a little more comfortable to pocket.
For items you carry, size matters -- that's why many people prefer smaller/lighter cell phones, ipods, laptop computers, etc.
Size/weight isn't so important for a flashlight you leave in the car or toolbox until needed. So there are various usage scenarios.
A single cell CR123A light packs a good amount of performance into a small package. At the high discharge rates typical of LED flashlights, a single CR123A has more storage capacity than two alkaline AAs.
2x CR123A lights are more difficult to safely convert to rechargeable use. A few can like the Surefire U2 can takes a 18650 or 17670 cell, which is essentially twice the length of two CR123As.
By contrast, many (though not all) 1x CR123A lights can use a rechargeable RCR123A cell. If you use a light much, buying 2x CR123A primary cells every operational hour can get expensive.
2x CR123A lights usually have more output and/or run time. However newer emitters (e.g, Cree XR-E, SSC P4) are so efficient that a single cell CR123A light has sufficient output/runtime for many applications.
Those same advances may reduce the need for 1x CR123A lights in favor of 1x and 2x AA lights. E.g, the Fenix L1D-CE and L2D-CE. They have many output/runtime options, using your choice of alkaline, rechargeable NiMh or Lithium AAs:
http://www.flashlightreviews.com/reviews/fenix_l1dce-l2dce.htm