My 2x CR123A spare battery carrier is my Fenix PD30. It doesn't look like a 6P, but it also isn't a piece of plastic junk. (Depending on how many lights I need spare batteries for and what I'm out doing, I may also use my Fenix P3D, my ASP Tungsten 2, and/or a generic 2x CR123A light as carriers.)
There are practical reasons for carrying my spare batteries in a spare light instead of just a carrier. While my PD30 isn't great at any particular task (with the exception of SOS), it's a decent quality multi-function light that can adequately perform a wide variety of tasks, making it a great backup for any of several different lights I might be using.
