Thanx everyone for all your quick replies. Though all your opinions are taken in account, my problem still remains.

I was thinking more in the line of: "The Technics has a superiour sequencer, because..." or "The Yamaha has extended viewing capabilities like scores and lyrics." (Don't know if this is true.)

In a nutshell: what features does the KN 2600 have that the PSR 2100 lacks? And vice versa...

Of course all of your other considerations are still very welcome as well.

Thanx again,

Martien

P.s. Since I'm living in The Netherlands, I'm not buying a second hand kb from someone in the USA, but thanks for the tip anyway, Dnj.