Yamaha PSR-EW400: I *thought* it was just a bigger PSR-E453!

...And it pretty much is, but you can't beat the luxury feel of this keyboard. It's just a joy to play and the speakers have mammoth output when compared to the (already perfectly nice) speakers on the PSR-E453. If you've got the extra couple of hundred dollars and you don't need battery power, then it's well worth it :)