Conclusion: I absolutely love this device, It has very much streamlined my workflow and I could not be any happier.... That is until Apple updated their OS to Mountain Lion and the device no longer works. So until Canon can figure out what Apple changed and create a workaround, I will be quite sad. :( *Note: I was told there was an update online that partially fixed the issue - but I have been unable to find the update on the drivers page. .
Pros: Solid Operation, Lightweight/Portable, easy to use
Cons: Poor build quality, Short battery life, Complicated controls/menu, unergonmic
Conclusion: Coupled my WFT-E4IIA with a Garmin GPSMAP 60CSx GPS unit and WOW! what an easy and quick sync. Extremelly accurate and the total time spent connecting was less than 3 minutes. Great combonation unfortunately the 60CSx is becoming hard to find. Most of the others Canon reccomends are already discontinued.
Conclusion: When I purchased unit I never thought about transfer speed, and being used to wire connection was used to 3 or 4 second turn-around to evaluate. I shoot 150 shots in a 1 1/4 hr portrait session, this piece would add 45 min to that and cause loss of momentum. I wish I had understood how slow a RAW transmission is compared to simple wire hookup. Probably ok for jpg files, but that doesn't work for me.
Conclusion: Very nice accesoire for EOS 7D to work free in studio envoirment (EOS Utility). But first you have to complete the settings or IP code, password etc etc to let it work. Not easy at the first time. Pitty there is no propper explanation. I didn't find one. This accesoire does need a better instruction manual or giving examples. I'm glad I bought this one.