Hello Frankieve,

It's difficult to answer because it's a question of personal taste.
I own this different keyboards because I find that any one is perfect...
I found the 9000 pro a very good kb , but I decided to sell it in attempting for the new Tyros 76 keys...(as a pianist I don't like 61 keys)

If I must add something and make a comparison Yamaha is an all-round keyboard ,sure, easy to use ,but with no surprise. I mean everything is allright but nothing special..
SD1 and Korg are not so (for me)all-round but you they can surprise you with styles and sounds. For my taste I find SD1 a little bit more complete but the mixing of the two keyboards is very interesting. The PA1 on the bottom and the SD1 on the top of my stand .I hope my answer was complete .
Greetings,
JJ

Greetings,
JJ