Originally posted by Dnj:
Ian there is no way around the great STEREO sound with two separate units with the Yamaha Arranger units....we already know that....it's just a matter of convenience with the Bose minus the stereo sound...
in some very small situations you can certainly get away with a non stereo sound while playing even though you as a musician inside know its wrong & have to take one for the gypper. 
The Tyros sounds good enough to overcome any issues in mono. Go for it. Only you will really know the difference. Your clients won't know or even care. They will hear the music, the song, the voice. Stereo will mean nothing to them. Most people are just not that sophisticated musically or technically. They will listen to the song.