You are right.   Right after my post, I thought to myself, why don't I call AJ?   I did that just now.  Had a a very nice talk with him.   He answered a lot of my questions for me, that gives more assurance about Ketron products.   I sure like Ketron sounds when it comes to orchestra/acoustic instruments.   
AJ confirmed for me that indeed the SD7, SD40, and other high end Ketron models have the same vocalizer engine.
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"You Shall Know the Truth, and the Truth will set you free." John 8:32