As important as the displays on BOTH arrangers are, do you find it a hassle to have to squint under the top keyboard to see what's going on on the G70? Plus, as chas says, having the manuals THAT far removed makes for a more tiring arm position, and makes for less accurate moves between keyboards.

If there's room at a gig, I might be tempted to put them in an "L' with the Yamaha on the right (or maybe on the left, it depends how you are using them). Are you triggering the Yamaha from the G70? Or vice versa? If so, 'L'-ing them up could make for a bit less arm-strain, and give you easy visual access to both...

But if you DO go 'vertical', lining up the 'C's (which this picture doesn't have them at) makes for more accurate jumps... (but I'm sure you already knew that)!