I've had no problems at all with any Ketron keyboards. I have owned X1, SD1, SD5, Midjay and now Audya.
The older Ketron operating system does involve a learning curve, but once you grasp it, it works great.
The early Technics boards, including KN1000, 2000 and 5000 were way ahead of their time, but that time has passed now. You are on the right track, for certain, particularly since Technics is no longer in business.