If you don't mind me asking, what feature(or lack there of) did not meet your criteria?
I can't find an option that is momentary on the tailcap button. I've come to the same conclusion as esrice on this. You will push too hard when you think you won't. And when you release, the light will stay on when not expecting.
This is the same reason I release the slide with a power stroke, rather than pushing down the slide stop. I know I can perform that action no matter what. It is exactly the same motion, regardless of whatever semi-auto pistol I pick up.