I am a wedding photographer and for the last two wedding seasons I have been happily using 3 600ex-rt flashes. One on camera and two off. I used to set my on camera flash to ETTL and both off camera flashes to manual mode. I controlled the output via group mode on my master flash. For a while now I have been setting all of my flashes to manual because I can get more consistent light and the batteries last longer. The only time I would use ETTL on my on camera flash is if I for some reason had nothing but air above and around me and needed to point my flash straight ahead.
Like I said I love the flashes but I have run into a few areas that I call "dead zones" where the radio signal gets screwed up but those times have been very rare. My biggest complaint is that even at low power settings like 1/32 or 1/64 I find that my slave flashes will go into thermal protection mode which cause all three flashes to stop working. It really doesn't take much for these guys to stop working. I don't ever remember my 580exII and pocket wizards ever doing that. The only way to correct the problem is to turn off the slave flash that is "overheated" and then turn it back on. Often this happens at a very inconvenient time where I can't go across the crowded room and make the adjustment. But I have learned to deal with this.
A few of my friends have dropped their flashes which has caused the radios in them to stop working so I have been looking into getting backups for my 3. Instead of just buying three new 600s I got to thinking that I really don't need a backup ETTL flash and that I would actually probably prefer just three manual flashes with a simple trigger. As nice as the 600ex flashes are, they are more than I need feature wise. However, they do lack in power sometimes.
After a little research I came across these cheetah lights: https://www.cheetahstand.com/A-New-Bare-Bulb-Flash-Arrives-p/cl-180combo.htm
They seem like they would do everything I need them to do at a wedding reception and outperform the 600ex flashes in terms of power. The only downside would be the lack of ettl which I hardly use and the added extra trigger mounted to my camera since it won't be in in the flash.
Anyone have any experience with these flashes?