I bought a Sunwayman C20C last month. I guess I got the old model as it still has the Tomahawk name and XML-U3.
I emitter swapped it with an MTG2 and swapped the driver with a 3.04 amp Nangj 105c with zener diode mode and DrJones Lumodrv firmware. I replaced the switch with a Radio Shack micro momentary tact switch. With this mod, the output is around 2000 lumens on 2x IMR 18350. It's much brighter than my 1x XML2 lights, but it's all flood. At full power, the modded light gets hot extremely fast.
Still a nice EDC though. I like the shape of the C20C. Feels good in the hand, and unlike most 1x18650 lights, it's small enough for EDC pocket carry.