Scott: I agree that the Tyros/9000 Pro/PLG150-PF are likely all sampled Yamaha grand pianos... but at least two out of these three sound different: the 9000 Pro and the PLG150-PF. That's why the PLG150-PF is offered as an expansion option for the 9000 Pro, as an upgrade. Now what I'd like to know is how the Tyros acoustic grand directly compares to the 9000 Pro and to the PLG150-PF. Simon's Tyros grand piano MP3 sounds on par with the 9000 Pro but my initial reaction is that it does not sound better than the PLG150-PF. I would like to hear a couple of test midi files played on all three for comparison. In many people's mind, the acoustic piano sound is one of the most important factors in choosing a keyboard - so a shoot-out could be enlightening.