Hello, all!  I just received my JETBeam BC20 today and I'm pretty stoked!  My initial impression is that it's a lot of light for the money.  It's rated at 305 lumens and while I don't have the gear to test that claim it is incredibly bright- much brighter than my Surefire E1B, and Surefire is notorious for under rating their lights.  It's well made, very solid feeling with very nice machining.  It takes 2 x CR123A batteries and has a removable pocket clip.  
The main thing I love about it is that it only has 2 modes!  The very nice forward clicky simply activates the light in whatever mode you set it.  With the bezel fully tightened the light is set @ full power or 305 lumens.  A 1/4 twist or so of the bezel puts it into low mode.  Dead simple!  If you wish to use it as a "tactical" light to disorient an opponent simply point and press.  For low mode it's easy to set it to low without even looking at it.
Finally, it's IP8 waterproofed and only $33!  Pretty good deal.  JETBeam has a pretty good reputation for quality so I expect it will hold up well but I'll update if it doesn't.
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“I'd rather have questions that cannot be answered than answers that can't be questioned.” —Richard Feynman