Not ETTL, but the Skyports
are reliable wireless triggers/receivers, and under $300 for a universal set and one extra receiver.
I tested the cheap ebay riggers and could only get 6 out ten times to fire the flash (a 430EX).
The Skyports just don't misfire. I was testing batteries in a 580EX II and it fired every time for over 100 pops.
I've posted these pics before, but I used the Skyports with a pair of 540EZ flashes to shoot high school basketball. Hundreds of shots during a game and no misfires. The flashes were set on manual at 1/4 power.
I don't know if this helps to answer your question, but it's all I have.
Thanks
Mike
Set up
Test shot from far end of the gym
Sample photo