I am very happy with both my 600-EX-RTs and the ST-E3-RT ... they deliver every single time without fail. I think Canon did a very good job ... Canon did not make any false claims about this product ... it delivers what Canon said it would.
As much as I don't like the lack of 2nd curtain sync, etc. I think Canon did a reasonable job with the system. They are, as far as I know, the only company to incorporate a radio transceiver into a flash. Which is saying something. I'm kind of surprised no 3rd party manufacture, and no other camera manufacture has copied the system. Not having to deal with separate radio transmitters would be awesome for quick setups (and to avoid having to charge extra sets of batteries).
I don't really expect them to make the system comparable with older flashes or other brands, after all they want to sell as many 600EX-RTs as possible. And I also fully expect them to hold out on the 440EX-RT as long as they can; after all they have no real competitor for this kind of integrated system yet - and the market rules.
I'm currently on the edge between using the RT system for convenience, or going with Phottix to get second curtain sync and studio strobe compatibility... I am disappointed they didn't put 2nd curtain sync in, since then I would have been sold on day one - but for most people I suspect it's a great product.
Having said that, I'm all for writing Canon to ask them to add these features. It may do nothing, but at least it'll make them aware of the demand, and maybe the next generation of flashes will address those issues.