Hi, I had 2 SD1s, and now I have the Tyros2, the issues I had with the SD1/SD1+ for ME, is the polyphony, is only 64, and let say,a single note in the right hand is actually 3 notes, so, as a pro player that do not sing, I rely in a strong lead and that has some "choke notes".
The SD1 has wonderful sounds and styles, but for me, it did not work well, in fact, I became the Phoenix area consultant on the Ketrons for most pros in the area, so, I am not knocking it, I loved, perhaps when a new Ketron flagship with at least 128 notes polyphony comes along.
In the mean time, I am very happy with the T2, yes, I do have some tone generation wishes, and is not that Yamaha does not have the know how, only they choose no to include great sounds in certain areas. So I am waiting for my Korg PA800 to compliment the T2.