I have 7 600EX-RT’s, and a wide variety of studio flashes and have been bouncing on camera flash since the 550EX was new. The 470ex Ai is an amazing tool in the right situation and in my opinion the only thing it lacks is the RT so it could be the on camera controller for remotes. The auto bounce functionality is amazing and I find the best use for it is when you are going from portrait to landscape mode continually, it just tracks what you are doing and always ends up where it needs to be. You can even set the bounce angle as normal and then get it to adjust for the different orientations.
For fast moving event style photography, family gatherings, receptions etc etc where I can use a single on camera flash it is my first choice.
OK, after watching a few demonstration videos, yes, I agree, the semi-automatic AI mode that compensates for orientation changes seems a beneficial function (that is, if the orientation change of the camera is in the right direction such that the flash can compensate for it, obviously.) Might be nice.
I rarely use speedlites on camera, for in most of my setups I only put the transmitter on the camera and place the speedlites somewhere in the room. And in those rare cases when I use the flash on camera I don't use slaves, so I wouldn't miss the RT function on the 470EX-AI too much, but I would still be annoyed not to be able to use the 470-AI as an RT-slave. So, yes, this is a serious lack of feature.
By the way, the MR-14EX II came out shortly after the 600 RT and it also didn't include RT, which I also found a very sad omission, because the ringlite would make an excellent RT master (it is only an optical master). At least the current twinlite MT-26-EX-RT has RT built into it, so that makes it possible to use 600-RT as RT-slaves in macro photography, which is great.
I really find it very weird not to put the RT function into every flash. Even a 90EX speedlite would be an excellent RT-master (it is only an optical master).