I ordered my Grav Taster the same day that I ordered my TM2 on some advice from a very trustworthy FC buddy here who's given me great suggestions in the past about other devices. I want(ed) and shopped for another glass stem in the higher pricetag range because I figured I'd want something more extravagant to go with my shiny new TM2. Although I still browse all the glass shops suggested in this thread (so much cool stuff to look at), my desire to acquire another stem has quelled for the time being. It feels pretty good knowing how inexpensive and functional the Grav is while I shop at a much more controlled pace. I'm sure I'll order one more after-market stem at some point, but for now I'm pretty happy with my new setup.
Here is my temporary (may be permanant since I own more than one) travel situation:
There is a folded up napkin under one side of the TM2 to keep the button propped above the divider to avoid continuous button press. The OEM short stem is in rolled in the kleenex next to the ligher. And my Grav is also rolled in a kleenex in the upper pocket. Works great, but as with the stems, I'm sure I'll keep an eye out for something better, maybe with individual pockets or straps for each stem would be nice.