Got myself a Casio WK500 recently and here is a review of my workstation keyboard.
It comes with a nice palette of sound and rhythms. You get 670 high-quality voices, 200 styles (comes with a Rhythm Editor), auto-accompaniment, and 48-note polyphony for playing complex arrangements.
Other features on the Casio WK-500 76-Key Keyboard include 15 digital effects, auto harmonizer, 200 presets, arpeggiator (90 types), song expansion, and an SD card slot for song storage. You also get a pitch-bend wheel for added control.
When it comes to recording, the built-in sequencer will let you record up to max 5 songs, each made up of 6 tracks.
Other recording related features on this Casio keyboard include a USB MIDI interface, line & mic inputs, and sampling feature that allows for 10 seconds of sampling.
The built-in speakers are good, though I am using a Behringer keyboard amp for hearing the sounds from my Casio WK-500 76-Key Keyboard and I'm really loving it.