While you could buy a PC/Laptop and load it with VST's that would rival most of the sound capabilities of the Oasys, it would not be possible to put together a PC/Laptop that could match the real time performance controls and GUI integration of the Oasys. That's a big selling point for the Oasys.

If the Oasys were truly "Open" then Korg could have bundled the Oasys with professional grade DAW software such as Cubase or Logic and that would have taken care of the DAW problem. Wersi has included Cubase with their OAS system for many years and those who use it see the power an all in one package can offer.

The Oasys does have the capability to utilize a mouse and a larger screen (the hardware exists inside the Oasys for these features), Korg just didn't make that hardware accessible to the end user. Korg has done everything in their power to claim the Oasys is open ended but Korg kept it closed by only utilizing Korg software and Korg updates. Korg could have taken Wersi, Lionstracs, and Open Labs queue and offered a much more open ended system that would have significantly benefitted the end user but they chose not to. The reasoning for that is highly questionable but I'm sure greed had a lot to do with it. If you control every aspect of the instrument then any additional software must be purchased through the manufacturer and not a third party.