Did you notice that the PSR540 looks like a toy compaired to the PSR640, and PSR740. I bet they did that on perpose so no semi-pro musician would even think to buy it. I don't think the PSR640 has twice as many features as the 540 to warrant the $400 in extra cost. I own the PSR540 also, and the same day I got it I was already recording midi songs. My next project is to create styles with it.