I like the switch system on the Swerve. It gives you tactile feedback so you'll know if the light's on or off without having to visually check.

I somteimes wear a tail light on my day pack when commuting to work. I can reach the switch but I can't see the light. With the momentary push button designs I currently use, I can't tell what mode the light is in. The Swerve will remedy that problem.