Just to clear things up a little, I have installed a few 222k receivers with these. I have also played with the remote a little. The 2 way features do not work with any receiver except the 222k (and the 722k when it is released). I have no clue if this can be fixed with software updates for the other receivers. With that said, the remotes will work as standard 1 way learning remotes for all ViP series and DP/DPP series receivers (with the exception of a UHF remote set to Band B will only work with ViP). I have no clue which Legacy receivers it may or may not work with.
The 2 way features allow you to save remote settings (Device Codes, Learned buttons, etc.) in the receiver, and save receiver settings (timers, prefs, etc) in the remote. This can be very useful if either the remote or receiver need to be replaced as you will not have to go in and set all of your settings.