Dan and George et all.
Yes, playing voice/samples is different from the vocal kit voice/styles. To get an idea of what these sound like, LOAD into the X-1 the Contemporary sounds, LOAD the pattern 'Vocalize' ... and just listen.
The difference?
* With the vocal kit (Loaded into RAM in X-series/on board in SD-1), the patterns are pre-programmed/determined. When you play a pattern that uses this kit, you should hear the same parts looped (every say 4, 8, etc measures). The vocal kit comprises of various vocal samples assigned and accessed via different keys (you can hear the independent parts in the X-series via accessing the RAM banks once you have loaded the CONTEMP sounds... similar to accessing your KICK/BASS drum, congas etc in your STANDARD drum kit when in DRUM EDIT mode.
*Using on board RAM, you can actually sample a sound and play-back with a style (just as you would play back say a PIANO voice). With the SD-1 sync-groove tech expanded to sync wave files with patterns/midi files, I believe you can further more adjust the sampled tempo to match current pattern/midi file tempo but still maintain pitch (and vis-versa). These voices are however NOT played via using a style/pattern. They are played using the RHS keys ... just as you would play any other voices on the keyboard!
A good example of this would be to sample a live choir singing "We will be heard" in the key of 'C'. Now upon playback (after temp matching/editing) using say an 8beat style, call up this new sample and play a 'C' note on the RHS for the first 2 bars "We will ...". Next play an 'F' note on the 3rd bar "...be heard". You could further enrich this by playing complete chords on the RHS. (Note: With the X-series boards, you will notice different tempos/pitch as you add more keys to your chord). As George mentioned, in the SD-1 this is similar to ROLAND's Variphrase tech.
This should be exiting!!
AJ