The Harmonys can accept commands learned from your original remotes and you can also input hex code (if available) for commands. If something's not on their site (which is rare), or if you want some non-standard customization, you can call their tech support and they can do it for you. The advantage to the MX-700 (and up) is that you can do everything yourself, as well as have macros on any button you want. With the Harmonys, your only real macros are the "activities". That's a real problem for me because I have macros all over the place in my configuration.
OTOH, if you want something that's quick to set up and easy for the whole family to use, the Harmony's are the best option in their price range. They just don't have the overall horsepower of the MX-700 IMO.
