Hi The Art of Sound
I don’t think Lionstracs was actually criticizing the OASYS (Trying to explain things in a language that is not native to you, causes all sorts of problems) but is pointing out the features that the Mediastation has over the OASYS, which includes being able to use whatever manufactures sound generation system you require. (The OASYS is limited to its own sound system)
Adding a computer to your keyboard gives you a great wealth of software for you to use, unfortunately it involves a lot of work to set up, and if you are gigging a longer set-up time, (Also the more mechanical connections you have the more chance of things going wrong) in a studio this is fine as once it is set up, you don’t have to worry about it, but most people (Both Home and Pro users) just want to switch on and play, and this is what Wersi and other open keyboards give you. (All the power and software of a computer, with the ease of use of a Switch On and Play system)
Sound modelling is the future (All the new Hammond Organs use sound modelling to reproduce the old Mechanical Tone wheel sound) however up until recently, computers have not been powerful enough to achieve this using multiple layers. (In truth even the latest CPUs have limitations when it comes to playing multiple and highly complex modelled sounds simultaneously)
Sampling sidestepped the problem of CPU power by making recordings of the original instrument, and playing that sound back when the use presses the key. (The more samples that are taken, the more of the nuances of the instrument can be captured, (And the more memory required, hence the use of disc streaming) and this is why the larger sample sets have a stunning sound quality, that becomes almost indistinguishable from the real instrument.
Finale point to note, the latest version of the Wersi OAS system (OAS 7) has now gone beyond just using its own sampled sounds, and 3rd party manufactured VST instruments etc, (Although they are still a great part of its arsenal) by incorporating multiple sound synthesis and real time effects. As an example if you play an FM Piano sound, it is no longer a sample that you hear (Samples are available if required) but is produced exactly the same as if it was being played and produced on a Yamaha FM Synth, (DX 7 for instance) likewise effects like Wha Wha, Flanger etc are now produced in real time. (Not samples of the effects)
I hope the above clarifies things, and I also hope that manufactures continue to push the technology boundaries well into the future.
BTW, is there any chance that the Karma engine will be made available as a fully featured VST?

Bill