All the photogs I know who have the 600EX-RTs have been waiting for f***king ages for Canon to release a 430ex-RT. I would much rather have a Canon Speedlight than a 3rd-party option, but since they seem not to have any interest in releasing a mid-range RT-flash they left the door wide open for 3rd-parties...
The flashes are a blatant copy but at least the YN-E3-RT will have a built in AF-assist beam, which is a big plus for dark environments.
I already have three 600's and I'm not willing to fork out another $1,300 for two more, that don't need to be that powerful.
I got 5 of them at the 373$ refurbished pricing and it's still cheaper than previous gen 580exII + TTL Pocket wizards.
I agree the 600ex flash is a better value proposition than 580 with pocket wizards. But pocket wizards can be used in conjuction with other flashes as well. That said, the 600ex flash radio system is incredibly reliable. The only time it didn't fire was when I was over-zealous and didn't wait for the flash to recycle.
Also the build quality is great. An assistant dropped one of mine into water a couple of weeks ago (fully submerged for a few seconds before we could fish it out) and it's still working fine, no issues.
Eos: 1Ds-III, 5D-III, 6D, 60D | Canon EF: TSE-24L-II, 16-35L-II, 24L-II, 35L, 40STM, 100f/2.8, 135L | Wishlist: TSE-17L, 200f/2L
Tamron: 24-70VC, 70-200VC, 150-600VC | Samyang: 8mm-T3.8, 14mm-T3.1
Crazy Ideas: TSE-90L-II, 40f/1, 100f/1.4, 35-85f/2, 100-300f/4_1.4xInt, 500f/5.6_1.4xInt