The only things I'll miss with Tyros2, of which the SD1 includes are:

1)audio sample drum loops synced to accomp styles
2)61 vs 76 keys

Other than that, I think the Tyros2's SOUNDS & STYLES, and OS navigation outshine the SD1. The SD1 came out even before Tyros1. Perhaps it's time Ketron come out with a 'new generation' flagship arranger keyboard. Any news of this? - Scott