i've just got the chance to play a E50, and i can completelly agree with what george said.
e60 is a (much) more professional look and feel than e50, and the difference in price is well worthy. the keys are longer and they feel more firm and respond in a very pleasent way. they are no g70, but the feel is very good.
now, of course is different for each of us, but i surely wouldnt pick e50 or psr3000 over the e60! you eventually get used to whatever you use, but why not get used to something good?