Quote Originally Posted by jrw View Post
Wasn't aware that the Flex system is capable of supporting 5 flash groups which is the big upgrade item for me
It doesn't. It has 3 just like the old Canon tech. It would be SUPER cool if Canon came out with an accessory like a FlexTT5 that could sit on older 580EXs and 430EXs, etc and allow them to be RF triggered by either the 600EX-RT or the ST-E3-RT. I feel like they would haven't mentioned it in the press release though. Who knows, time will tell. For people just getting into the game though this is great as I am sure that future units will be backwards compatible. I see this as a rather large leap forward in Canon flash.