To me the premise behind plug-out sounds neat, but really I don't see a huge difference in what it fundamentally different than what the Miko/Neko stuff did from Open Labs. And, unfortunately here's how that worked out for them:
http://us.openlabs.com/2013/index.ph...egacy-hardware
What will matter more about this System 1 synth, I think to many people, will be how it works when truly integrated with the DAW in the same way the Virus TI or UltraNova integrate -- for example audio over USB with low latency, using the DAW plug-in to instantly visualize changes made on the hardware when the synth engine is running fully on the hardware, etc.
Granted, even if they take a piss and say "well if you're having latency issues you need to run the synth engine on your host computer and just use the keys and knobs as a controller", there could still be a very big benefit here that other vendors have not yet tapped. That would mean that you could potentially use the plug-in in your DAW during the initial stages of your workflow using the PC's CPU just to speed workflow along, then when the track gets busier and you need more processing power you could potentially off-load the processing to the synth, feeding it into the sound card via audio in.
However, for that to begin to excite me at all, I'd need to hear some really impressive sound demos from this little green light box, which I haven't heard yet.
I also don't like buying anything based on a promise of how good it's going to be some day in the future. The SH 101 module is not yet released so nobody can review it, I haven't heard how much Roland plans to charge for each module, there's no guarantee the module will be authentic, and nobody knows which modules will really be available. Like most things, if there isn't a strong revenue stream tied to the modules, Roland is not going to spend a lot of money doing the hard part (making the software synth sound top notch).
So I think it will be another 2-3 years before I can really look at the System 1 and say whether or not it's something I'm remotely interested in.