'Do you mean the switches?'
the board, that is the black cherry together with the metal plate. they just feel nicer (more dampened sound, without being at the same time hard, like the filco ones for example, and more solid feel, less vibration from the caps/switches) than the later wyse keyboard. maybe that has to do with the thickness of the plate, PCB layers, plastic quality, lubrication used etc.
even the cherry stabilizer found in wyse is much nicer than the ones you find in cherry keyboard, and it is a lot easier to remove/change than the filco costar one.