This music workstation got rid of some previous classical Ensoniq features, such as polyphonic after-touch (replacing it with a mono version) and full sound editability.
Most problems were compensated for by an improved 64-note polyphony, high quality 24-bit effects and a quick (but not fully editable) sequencer.
All MR versions could house up to three expansion cards, each one holding up to 24 megabytes of samples and sound data.
The MR-Rack (which actually appeared before the keyboard versions) shared the same architecture and sounds, with the obvious exception of the sequencer and drum machine.
Also, while the rack version could take the same wave expansion cards of the keyboard counterparts, it was not compatible with the flash ROM sample-loading add-on.