travlin'easy, well, there was time when there was such a keyboard as PSR-550 (not "S"), which was also a low end keyboard, but there were such functions as 'freeze', or 'direct access' in it. But then Yamaha thought 'the users of low entry keyboards don't want this sophisticated stuff, let's not confuss them anymore!' So, now everything below PSR-S750 (which is more than $1,500 in Russia) represents this concept of simplification. But the same thing is happening to all kinds of stuff, not only keyboards. Even to LEGO’s )