I think portamento is primarily used for solo voices to get a smooth change. My old Roland XP-60 and Yamaha EX-7 had this feature and it worked really well.. Dreamer is right too.. You can program a voice so that the changes are smoother.. You have to adjust the release rate of the sound.. I remember doing that when I had the Casio MZ-2000.. I too was using strings and I wanted a smooth transition so I adjusted the voices release rate and made a few other small adjustments and got the sound to work...

[This message has been edited by squeak_D (edited 08-12-2002).]