From the demos it looks like the 970 is a completed version of the 950, just like the 910 was a completed version of the 900. (The 900 & 950 operated and sounded more like Beta versions, as did the Tyros, Tyros 3 and now the Tyros 5)

As with most arrangers it is not usually very beneficial to upgrade to the next model that comes out, but instead to wait for the following version to appear.

That’s my take anyway.

Bill