This video, via perfectcircuitaudio, demonstrates the drum sounds of the Roland JD-Xi.
The JD-Xi has four channels: drums, analog monosynth and two digital synth.
The drum sound library includes many types of electronic and acoustic kits. Drum instrument assignments are labeled above the keys for quick identification. You can customize the kits by adjusting filter, envelope, pitch and pan parameters on individual drum sounds.
The Roland JD-Xi has a street price of about $500. See the Roland site for more info.