"it's a common problem with a simple solution." Sure is, call Frank about that PA4X!
Pa4x is definitely a solution,an expensive one at that, as is the Tyros5,..same reason I couldn't use the KORG Pa900 also which is worse then the S970 in visibility.....
i can see your problem... maybe if you set the s970 at a slight angle, it would improve your vissibillity?
oh and have a look at the Casio MZ-X500 that one just has its whole front panel at a nice angle for improved reach and visibillity. (just kidding)
personally i am very happy with the tilting screen on the Tyros5 since its on the top position, thats a must have. I do feel your pain, with 970 having bad vissibillity and Tyros being to heavy to move around. nad there is no high end arranger thats both light and has a tilting screen...
and sad thing.... i dont see Yamaha making a PSR with tilting screen nor a much lighter Tyros.