Bad Mister, who's a keyboard wiz, made this post on the motifator forum. When you guys read it you'll see why I'm saying its more than just midi and sysex.
The new Motif XS VST editor and the Motif-Rack XS VST editor will be the first VST3 hardware editors. So it may indeed be a bit different for everyone to understand because you have not had such a thing yet.
The significant thing about it will be how MIDI data and the audio data generated by that MIDI data is handled. With any VSTi you basically are recording MIDI data in your DAW... the MIDI OUT of that data is echoed to (routed to) a synth engine that generates the sound... the returning audio (that is, the audio generated by that synth engine) is shown in a special audio lane ("invisible track" as the Steinberg documentation calls it)... that returning audio can be in turn routed throug VST Effects, can be automated using the DAW automation functions, you can, depending on your version of DAW software, use a function like FREEZE. And of course, very significantly you can use AUDIO MIXDOWN to render the track into a full audio track... (quite naturally, but significantly, the rendering of the data is realtime... because the Motif XS and/or the Motif Rack XS tone engine are external devices).
The VST3 version of the editor does not use Studio Manager, but instead is launched like the GUI for any VSTi. It is however, a multi-timbral VSTi... and while you can have multiple instances of the editor running simultaneously, if you truly understand what is on offer you can see it would require multiple Motif XS's... Each Motif XS or Motif Rack XS you own would have its own editor interface... so, again, the VST3 editor for the XS is a multi-timbral editor.
You can route signals very flexibly through 8 Stereo buses... this keeps it simple and yet lets you work to process your music as your require and commit data to audio tracks in Cubase. So the tracks you want to process externally (say with Effects inside Cubase) can be routed on the VST audio buses and send to Cubase... this will give those of you using the 16 bus firewire interface to your computer a huge advantage in routing/processing possibilities. Those using a stereo audio interface will be able to process the overall signal coming to the DAW.
So you will find advantages for both those working on individual track processing (using the multiple audio outputs available via firewire) and for those just simply wanting to finalize mixes from the data generated by the XS tone engine.
Cubase Automation and VST SOUND select tools are available meaning you can work in the computer environment in a consistent manner if you are used to working with VSTi.
In short, the VST3 editor will benefit those that work (record) in the computer DAW environment and who are interested in recording MIDI and Audio in Cubase.
The VST3 protocol features 'dynamic' allocation of CPU resources, integration into VST SOUND/Media Bay so that you can tag your own sounds and create a very useful librarian categorization function for your Voice data.