You'll get lots of opinions as to the "best" light sporting the new XM-L. Obviously then, here's mine. I recently got an EagleTac T20C2 MK II, and I'm very impressed with it. It definitely isn't mini 123 sized, but for the amount of light and runtimes you get, it's pretty impressive. Portability? I guess it's as you portable as anything else depending on how you want to carry it. Belt sheath? Pocket? It comes with a nice sheath and that's how I carry it, but if you don't wear skin tight pants, or wear like cargo pants, it would carry easily in a pocket. I bought mine about 2 or 3 weeks ago and it came with the XM-L rated at 550 emitter lumens, or 430 OTF. I've purchased some additional drop-ins for it, including the one I just got today, the new HO (high output I assume) XM-L T6 rated at over 720 emitter, 580 ansi lumens. That's one of the reasons I got this EagleTac. They have several user replaceable drop-ins available for it which makes it extremely versatile! Takes 20 secs to swap out modules. I have an XR-E which throws very well, and a nice neutral tint also, plus the older XM-L, which will be nice to have as a "back-up" in case something would happen to this new HO drop-in. The UI seemed a little weird at first, but after playing with it a little bit, it's really not bad at all. Good luck with your search.