What i currently prefer is a powerfull tablet with touchscreen .. (microsoft surface pro book) ... the biggest advantage of having that separated is that you can do a lot of the preperations and sound design from your lazy chair in the livingroom and don't have to spend hours in your home studio away from the family..
Very nice. The Surface Pro is amazing. I have an i5 Acer tablet myself but it's used for so many other non music related things that I can't afford to devote it to my music. Would love to have a Surface dedicated for music only. I'd want the 16GB RAM / 1TB version though. Expensive.....
But i can see much of the charms and advantages of a single all in one on stage... altough if your key functions as audio and midi interface for your laptop/tablet.. you have overcome much of the disadvantages of all the cabling issues
Yeah, I just think you would have more flexibility with a system like this. People who want just a single instrument can keep it configured that way, those who want it the center piece of their studio can use all manner of connectivity over USB 3 and so on.
Or, you can have both options at the same time. A single machine for gigging, and when your back in your Studio, connect it to everything.
There's not really much of a leap in any of these idea's. It's really as simply as stuffing a fast laptop in many ways into a Keyboard Case.
Heck, if I could buy a Keyboard that acted as a Surface Pro 4 dock, that would even do me. Just drop the surface into cavity where the screen would normally be on a keyboard.
lol.... A few strips of velcro could even come in handy for a quick hack job.
Still i think the problem lays with the software side of things... being a fervent fan of arrangement and arp's there is no single part of software doing it all... and there is no easy comfortable way to combine the few i use into the perfect setup.
Just thinking out loud here, but it sounds to me vArranger maybe of great interest to you.
https://www.varranger.com/
Built from the ground up to be operated by a touch screen and it seems to cover most things a high end arranger keyboard does. Supports VST's too, so it sounds like a great expandable platform that would offer you the simplicity to even play the system 100% live at a gig.
Regards
Sharp.