Hi Paul
It's probably easier to sequence songs on the Tyros, it depends on what you are putting into the song. It may be just a beginners problem but I find the M3 harder to multi-track than the Motif, it's the difference between the 2 operating systems. With both these keyboards you can make patterns (easier on the Motif) and chain them together to make a song. You can make these patterns by either playing them yourself or recording one of the many performances (Motif) or combis (M3). The addition of further tracks is so easy.
The selection of voices is a lot easier on the Motif as you can organise your voices into a 'favourites' section - can't do that on the M3 so you have to know what you're looking for which means either making a note of the location or trudging through the voice sections.
The mixing function is better on the Motif and is based on the Mixing Console of the arrangers
One thing I do NOT like about the M3 is the touch screen, I hope Yamaha never go down this route - give me a knob anytime (oops

) or a slider.
I hope to be able to produce a comparison thread in due course.
In the meantime thanks for your comments they're very useful.
Cheers
Spike