Boo, the PSR2000, 9000 and of course Tyros, have extensive microphone processing, including 5-band dedicated e.q., two effects and compressor/limiter. Also, they have the built-in Vocal Harmony, with several pages of presets for that. The mic settings can be set to change with registration changes, or stay the same regardless of registration changes. There is also a "Talk" button that can be set to give an additional mic setup instantly.
In addition to the mic processing, the PSRs have a customizable overall parametric e.q., plus the capability to seperately e.q. each individual style part or voice.
I only need an external mixer when I have another musician playing with me.
To purchase all the extra processors that the PSRs include (even sampling on some of them) would cost more than the price of the keyboard itself.
. . . but no touch screen.
Don