As a Canon shooter, I was glad to see all the cool specs on the new Canon 600EX-RT and companion ST-E3-RT that Canon announced at the beginning of this month. Back before I met Scott Hargis in about 2006 I purchased the old ST-E2 (predecessor to the ST-E3) with a 580EX. They were pricey and the combination didn't work so many times because the ST-E2 couldn't talk to the 580EX I lost count. So I still have a bit of a bad attitude about Canon flash gear. I have to say, my attitude didn't get any better recently when I look up what the price is combo on Amazon. It will cost you effectively $1100 to have one off-camera 600EX and $1730 for two (2-600EX's plus a on-camera ST-E3).
I haven't tried these new versions, so I admit, I know nothing about how well they work. Syl Arena has a post about his hands-on experience with the combination and is positive about them. My question is why did it take Canon so long (about 5 or 6 years) to understand that the last version of this combination was a bad idea, wasn't reliable and needed to be redesigned to use radio frequency communication? In 2008 when I first saw Scott's presentation on triggering any flash with any camera for $33 I quit using my Canon ST-E2 and haven't used it since.
I would advise caution and skepticism before running out and buying into this flash solution because:
Sorry to be so cranky, it just takes me a long time to get over being ripped off by a major multi-national camera manufacturer!