it's NOT about playing a gig with the onboard
speakers, i'd be surprised if there were any out there that do that--it's just about having them as a convenience. when i'm just practicing
or trying out different features, etc. there's
no need to plug into a home studio unless i want to really hear it that way. i can take my kb out to my barn in ct when it's warm and
practice there..i can move from one room to
another, i can take it to another musicians' house to work out some things w/o an amp. (these are all advantages of a lightweight
keyboard as well. Furthermore, if the onboard
speakers have adequate power, as the E60's do..and the Korg..they serve as personal monitors on the gig in intimate situations and no other monitoring is needed.