+1 for Phottix Odin.
I have shot at least 10k shots with them, I haven't changed battery and the transmitter yet!! I changed in two of my three recievers, but they last extremely long on two AA's.
And the best thing, I have yet to experience a misfire or have an off exposure, I shoot mainly M mode, since they can be controlled from camera, but accoasionally ETTL and it works very well!
They said it would be a new firmware in July to deal with the ONLY issue I can think of, the Full stop increments when dialling power. The nikon version is 1/3 and while they said that would be VERY difficult to do in firmware for Canon, they have been on it for 6 months or so, and it seems it will in fact happen.