Rolex John,
Thanks for the Review.
I am not sure I understand why you didn't like the Tactical UI. Like do you mean for use with a handgun, specifically holding the flashlight in the weak-hand crossing under your strong-hand holding the pistol?
These lights are really light weight and I would consider mounting one on a tactical QCB rifle using a 25mm scope ring attached to the picatinny rail. For that I also think the monetary on function of the tactical UI would be useless since you would have to keep constant pressure on the switch using your support hand (It would be cool if 4Sevens made a momentary-on pressure pad for the Quarks but probably not cuz it would detract from the maelstorm G5/X7 offerings for use with the more common 1in weapon mounts). For such a use I would just click it on to do the raid/building search and the turn it off when I didn't need it. I could, however, see the momentary-on function working well for nighttime navigation but then you are too limited with the TUI because you are only allowed two modes. I think the Regular UI is preferable for such a use because it has quick access to Max and Strobe for the raid and/or building clearing, and easy access to moonlight and low modes for assisting nighttime navigation.