I have the same problems with my XP-80. I think the problem is with the sequencer's ability to play many simulataneous notes/sounds. I can, usually, have only about three simultaneous tracks as well. At first I speculated that the problem was polyphony. I thought that, since each patch is composed of multiple tones, perhaps each tone counted as one voice of polyphony. So, I counted the possible tones on the song I had recorded into the sequencer...they added up to only 34! So, I recorded parts into the sequencer using external MIDI gear and the problem persisted (I was using only 4-note polyphony on the XP-80 and no more than 3 note polyphony on each of the external instruments, so I had to conclude that the problem was with the sequencer becoming overloaded). From my experience, this is a problem with virtually any hardware sequencer (I don't know anything about such timing issues with software sequencing programs); my Korg M1 had the same problem, although I could seem to record more simultaneous notes on the M1's sequencer (but not many more!). I have never tried Yamaha hardware sequencers. I suppose what I am trying to say is that you may encounter this problem with any workstation keyboard. The onboard sequencer is great (very convenient; no other gear has to be turned on if you are using headphones) as a "scratchpad" for recording spontaneous playing and developing musical ideas, though.

I guess a way to successfully use the XP-80's sequencer would be to sequence only two tracks at a time and record them into a multitrack HDR (like VS880) and keep recording tracks upon tracks, using the HDR. (You can sync the XP-80 sequencer to the VS-880.)

I really like my XP-80, but am disappointed with the sequencer. Sound editing is pretty easy for not having knobs and the interface is, to me, extremely logical and easy to use. By the way, I very infrequently use the XP-80's factory sounds; I get virtually all of my sounds out of this synth from the expansion boards I have installed in it (I love their patches!). If it's the sounds you want, the JV-1080 and -2080, as well as the new -1010, have the same as the -80, but cost a lot less.