I have received my Cheetah V850 flash. It is well built and is about the size and weight as a Nikon SB-900. The V850 has the same output as the SB-900. I used a calibrated Sekonic L-758DR set to iso 200, zoom set to 50 mm and 10 feet from flash to light meter. The V850 gave an f-stop of 14 and so did the SB-900 and SB-800. Build quality is as good as or better than the SB-900. It is a totally manual flash and so you adjust the flash power rather than the flash or camera doing it for you. There are several key features with the V850. First, it uses a Li ion battery with a capacity to give over 600 full power flashes on a single charge. The V850 kit includes a battery charger for the V850. The Li battery is removable and replaceable. Also the recycle time between full power flashes is 1.5 seconds. No battery pack is required as is needed for the SB-900 to achieve high number of flashes and fast recycle time.
The second key feature is you can change the power of the flash wirelessly by using the  Cheetah transmitter and receiver. You can also trigger the flash with the transmitter and receiver. This makes it very convenient to adjust and measure V850 output when you are using a flash meter. I also own two Cheetah CL-180s, and they use the same transmitter. This means I can mix V850s and CL-180s in a single flash setup. I can control power and trigger both flashes with a single transmitter.
The third key feature is the battery meter that shows on the LCD screen how much remaining battery charge is left. I own several Nikon flash units (SB-900, SB-800, SB-600, SB-400 and two SB-24s. None of these flashes have a battery meter and so, you never know when to change the batteries.
The fourth key feature is the price of the V850. It costs a lot less than any of the Nikon or Canon flashes and many of the other Chinese flashes.
There was very little information on the Cheetah website about the V850 and so I researched the Godox V850 which is the same unit. It received several excellent reviews. The Cheetah V850 is a re-branded version of the Godox V850. There are several businesses on Ebay that are Selling the Godox V850 or a re-branded version of it. Why would you buy the Cheetah brand? Because of the support that Edward Tang gives his customers. If you have any problem, he will fix it. I have been purchasing photo equipment from Cheetah for several years. Recently I ordered the Cheetah Boom stand and it was lost by Fedex. I sent a message to Edward I received a phone call from Edward a few hours later and he had notified Fedex. I then received several phone calls from Fedex and in a few days the boom stand was found and delivered to me. For me, Edward Tang’s support is also a key feature of the V850.
Review by: Richard Simpson