I had a Sony receiver (STR-DE945) that had a bi-directional remote. It was worthless. The remote had an 4 line LCD on it instead of buttons for each source. So, when you wanted to change sources, the remote would query the receiver for what source it was currently on. So, on the remote, the LCD could indicate which source you were on. It was really dumb and took a couple more seconds to do simple tasks.

You can see a pic of it here.