Mike, wow ! what an excellent memory. Even I had forgotten the number of notes, but after re-checking the KN5000 manual, it is indeed 1800 (approx) notes that can be stored. But remember, that is the total capacity. If you use up all 1800 notes up for one pad sequence alone, you would have nothing left over to use for the other 2 'user' banks of 6 pads. Here's how it works:
You set the tempo, measure length, sound that you want to record. You then set the playback mode: 'sync to rhythm (in tempo)' or 'instant start (out of tempo)'. The manual sequencer section also records sustain, pitch bend, mod wheels, etc.
You can record, name, and store different Manual Sequencer Pad setups to load up with a specific song if you like.
Seems to me that the manual sequence pad feature will work for what you are trying to do. The Yamaha's mulitpads work similarly, but don't support the 'sync to rhythm' feature that Technics has. Also don't know the max number of notes supported on the PSR. Hope this answers your questions. - Scott