The Opteka works well with my XTi. Unless they've updated it to come with an N3 cable, you'll presumably need a different cable for it than the one it comes with (stereo submini to stereo submini), but if that's the case, you can buy the cable on Amazon for a few bucks. The two flash release mechanisms are electrically compatible; the only difference is the connector. (Why, oh why did Canon change to a nonstandard connector?)
About the only thing I don't like about it is that it doesn't have a mechanical power switch, and the batteries are not cheap. I recommend removing the batteries and carrying them separately when not in active use, because otherwise the receiver (at least) will run its battery down.