One could probably download the Canon manuals from their website and get some insight into how the Yongnuo works as they seem to be intellectual copies of the Canon gear. I have 3 600s and the ST-R3 and am happy with it all. It just works and is very reliable. I don't think I paid more the $449 for any of the flash units when on sale at B&H.
DStone wrote:
Bought a flash and the transmitters a while back to pair with my old SB600 (and as a back-up). Everything works just fine, but good luck trying to read the manuals. Even posted here on UHH asking if anybody had translated them into comprehensible English (nobody had). The system is very easy to use once you figure it out.