If it had made the promised 1200 horsepower, it might have been worth it.
The issue with the -14 is prop clearance, I believe. You'd have to redesign the wing, and even then I don't know how the ground clearance would be. Then, you'd also have to redesign the tail (to handle the additional power), and by the time you were done it would be an entirely new airplane.
The Cheyenne 400, with all it's advantages, still doesn't compete all that well with a CJ2. I just don't think there is a niche there for a super high performance turboprop, although they do keep selling Piaggios, so who knows...