It will all depend on your specific needs (or wants, in some cases), but, for me, I could get by very well on a Tyros3, S950, S910...even the S750 would be very giggable and also great for home use.
I am seriously pleased I wound up with the Tyros4, as having both the FSX keybed and being able to use SA voices in the styles, although not entirely necessary features, are incredibly good to have all the same.
The Ketron SD7 sounds pretty damn good in the demos, and it looks to have lots of useful features, but my biggest concerns would be reliability (and the possibility of dealing with any repairs) and followup support. I realize AJ is more than capable at his job, but one also must be concerned about what happens if, for some unforeseen reason, he needs to take some time off or decides to do something else.
Do they have a backup plan?
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.