DanO,
Clearly this functionality is not to replace a full functional studio But to complement it. For example, so many times I have to create a quick audio cd from the keyboard and I have less than an hour. Having CDR on the keyboard and the functionality to support it is very helpful.
Transfering audio part to the studio via a cd is sometimes preferrable than real-time transfer.
I do not see this keyboard as a mini-studio. I see it as a keyboard with new functionality to support those who already have a studio and do studio work. For sk880ps with all options: I paid close to $3000. If users in this forum are happy to pay $3000 for Yamaha PSR9Kpro, I think this is worth it.