Haven't tried doing it with a G70. Thing would be, you couldn't really audition it without having to change it to G70 sounds (might be able to do it with MIDI out, not sure about that) which would kind of defeat the purpose.

I thought that much of Yamaha's style editing and creation had to be done with PC programs, though. Or is that just the Mega stuff?

Yes, style assembly out of existing parts would be great to have in the box, but good grief! You've got to leave SOMETHING for MOTL and TOTL models to have over the baby of the family! Otherwise, how you going to sell a G80?