Vash, I have been using am import drop in for my Surefire G2.
Solar Force LC-XPG Cree R5 Single Mode Drop-In
I was so happy with their product that I purchased 6 more of their hosthttp://www.lighthound.com/Solar-Force-L2P-Flashlight-Host-for-18650--L2P-Host-HA-III-Black-Finish_p_3473.html.
I don't like the sharp crenelated bezel so I bought the smooth one for 2 bucks. They run on CR 123 rechargable. Its small like the G2, and fit in the back pocket nicely but the light out put is huge. I had Super Stingers and they were too expansive to lose so I have a bunch of those now. the one thing I like about their light is the simple on / off. One single setting, unless you purchase the three setting drop ins. There is nothing to turn or hold to keep the light on. click on/off, simple. Switches are replaceable for a few bucks. the draw back is the run time, only 45 min. so I have off the shelf 123 batteries in the car for back up.