Most of this review is based on the Quark MiNi AA since they are practically identical in terms of functionality. Aspects specific to this titanium version will be mentioned as necessary.

The Quark MiNi CR123, just as its name implies, is very small and light weight. It's made of titanium and has a smooth polished finish, although there are some noticeable machining marks, especially at the flat tail end. The head has a pretty simple design with a smooth bezel. Behind this is an AR-coated sapphire lens which allows better light transmission as compared to regular glass. A lightly textured reflectors focuses light from the LED which sits well-centered at the bottom of the reflector cup. The coating on the reflector is nicely polished and consistent with no noticeable flaws. The exterior of the head is mostly covered in diamond-textured knurling which provides ample grip which is good since the light is twist-activated. Viewed from the rear you can see the PCB with electrical contacts for the battery.

The battery tube continues its simple, cylindrical design. It's almost totally covered in knurling on the exterior, with a slightly raised section towards the rear end. There is also a small lanyard hole at the tail end for lanyard attachments. The flat end also allows the light to tail stand easily with no problems. Threads between the head and tail cap are slightly rougher as compared to the regular aluminum version. A well-lubricated rubber o-ring sits just behind the threads which provides a moisture seal. On the inside, the battery tube is cleanly finished and has a spring contact at the bottom which prevents the battery from rattling when the head is loosened while switched off.

If you're unfamiliar with any of the terms used in this review, click here for explanations on common flashlight related vocabulary.

The MiNi CR123 provides a total of 7 modes of output. From off position, switching it on presents the low output level. Subsequent off/on twists of the head within 2 seconds cycles through medium then high output levels. The remaining 4 output modes are strobe, S.O.S., beacon (hi) and beacon (lo). These are activated by going through 2 cycles of the low, medium and high output levels. So an overall sequence available is as follows:

Off > Low > Medium > High > Low > Medium > High > Strobe > S.O.S. > Beacon (Hi) > Beacon (Lo)

Take note that there is no memory functionality, so it will always revert to the low output mode first after the light is left off for anything more than 2 seconds.

Beam profile provided produces a medium sized hot spot with a smooth corona tapering off to its spill beam. The beam is clean with no noticeable artifacts. The review sample has noticeably cool tint. The low and medium output levels are achieved by means of PWM, though the frequency used is high enough for it to not be noticeable in practical usage unless you intentionally wave the light around looking for signs of this. Tests produced a maximum output of 156 lumens on a CR123 cell which is slightly lower than the advertised 189 lumens. Although not specifically stated, the MiNi CR123 also unofficially supports the use of 3.7V 16340 li-ion cell. You can use a 16340 cell for low and medium levels without worry, however high should only be used continuously for less than 1 minute at a time although you do get a nice boost in output measured at 255 lumens. This is because the small body of the light is unable to effectively dissipate the heat at this high level. Prolonged activation of high output on a 16340 cell will lead to accelerated degradation of the LED over time. Runtime is good relative to its output, well regulated on medium and low levels but curves gradually on high. There is also a quick initial drop to about the 90% mark as can be seen on the runtime graph below, which is not as bad as the AA model reviewed earlier.

The Good - Clean design and well-machined body. Respectable runtime performance. Compact and light weight.

The Bad - Nothing significant.

The Relative - Beam is clean with a noticeably cool tint. Uses a twist switch. Is able to tail stand.