These guys have some well made lights that are pretty practical. I use my Fenix USB rechargeable all the time. Everyone has phone charging station and portable solar panels on back pack these days, so USB is way more practical than a regular AA battery charger.
New this year, TK72R has digital incrementally adjustable output from 100 to 9000 lumen. It comes with strobe function and it is waterproof down to 2m for 30 minutes. According to Fenix, this is geared towards "group" activities . I guess if you are a boy scout leader or doing some group outings in the wilderness, this is a pretty useful tool to signal, find and guide a bunch of people. I think of it as the "Gatling gun" of flash light, or more like the German stick grenade!
UC52 is completely sealed 3000 lumen light and it is also waterproof down to 2m for 30 minutes. The battery can be recharged for up to 500 cycles. It also has digital intensity control and strobe function. The digital display is kinda a reverse of TK72R, it shows exactly how much battery time it is left. Pretty nifty.