John,
Your sentiments do you credit. And your experience with 'All The Things You Are' (bet you didn't do the verse ?), is something which many of us do as a normal part of our keyboarding. - And your overall point about 'moving on, learning and growing' via new technology, is obviously applicable to many.
Your 'moving on' also suggests 'not with Technics'. And not with the K7. But why not. ? The sequencer in the K7 is the finest there is. It's a tool, which if used to it's fullest, can enable a player to be transported into the realms of musicianship he never thought he had. !! - I mean of course, the 'realtime' multi-tracking function, not 'Easy Record'.
If you experiment in getting to know everything the sequencer will do, including the use of the Composer and Step record etc, you will discover that it can take you into realms of creativity, which you never thought you had. You can (if willing to be patient), finish up with a complete example of arangement and orchestration, which is all your own work. An expression of your musicality. - And it is 'THE TECHNOLOGY' of the KN which enables you to express your own musical abilities to their fullest. if you then consign your creation to CD, you have a record for all time of what you did.
In other words your 'moving on and learning' does not require you to obtain a different, and new keyboard. The inherent technology designed into the KN sequencer, will give the user a learning curve which is second to none. It's a wonderful tool, which, with detailed knowledge of it, becomes the route to producing amazing things. I doubt any other keyboard can do quite the same. If you can sit at this keyboard, and produce a 16 track recording of your own creation, you have 'the ultimate'. - Happy sequencing, Colin.