Hmmmm... are we sure the auto-accompaniment can follow the singer's tempo or is it only midi files as they play back that can do that?

Also, it doesn't make any difference to PSR2000 owners because they can already do this, but the Scorch XF function on the Tyros would be another reason all other PSR owners would have to upgrade. That's the ability to display real sheet music on the display from Scorch XF music files. That feature will hook a lot of potential buyers if they know about it.