I have a Motif XS7 and a Roland Fantom X6. The Yamaha has better sounds, but the Fantom is much simpler to operate, and of course is easier to transport. The Motif XS7 is heavy to take out, and is almost overkill as far as tweakability is concerned(over 6000 arpeggios). It has performance control simply by pushing a button on the face of the board. The big screen is helpful when setting up performances and with other tweaks. I like both boards quite a bit. The sounds on both(though better on the Yamaha)are great.
I owned a Casio WK 3800. I thought it had great sounds, but was very cheaply made. The keys clacked badly all the time. Reliability was suspect.