If I did not own what I have (and Roland was not available anymore), 
If I needed to buy a current arranger keyboard... it would be an easy choice..
Ketron (as long as my buddy AJ is here   

 ). Nothing tops it in sound or quality.
Over the years I have done side by side comparisons, and have listened to
other youtube comparisons.
I have recorded some comparisons and folks (regular non bias folks), 
have chose the Ketron sound over every other brand. (even Roland).  
 The only time I can recall  a nod for Roland over the SD7, was when I used the
Roland Integra7 (Supernatural acoustic sounds and drums).
Personally there were a few features that I had with the keyboards
I own...that no other brand could do or match, so I would not change.  
 But like I said, If I could only own one and it had to be a new current
arranger keyboard.. Hands down.. it would be a Ketron.
Roland has always been the best innovator when it comes to keyboards..
Ketron has also been good at innovation.
Korg and Yamaha.. not so much, If they didn't have innovation from Roland
 they would be way back. If you think I am wrong.. do some research.