I have played them extensively, yes. I teach at a high school in PA and we piloted a program last winter in which we featured a number of students, local pros, and guest artists performing on and composing for the Seaboard GRAND.
Shoot me a message if you'd like to chat further, but it's my opinion that your comments above are true and then some. It's been an game-changing experience for everyone involved. On top of it, the ROLI team has been unbelievably generous with our students and has great interest in incorporating their instruments (especially the new RISE controller) into the classroom.
Neil