I have my music room set up as follows...

The G70 on lower level (V-Stand).

The E-A7 on the top level (V-Stand second tier arms).

The E-A7 is slightly tilted to read and operate the controls
as well as playing.

I keep it simple, not midi'ed together.

I usually run the output of the E-A7 into the
audio in of the G70..(I can reverse this if I desire,
but I prefer the control on the G70).

I have the same styles on both keyboards.
But rarely use the styles on the G70.

This set up allows me to use the features of each keyboard.

I like to have the 76 keys for dedicated piano,
and the drawbar organ on the G70. Also specialty sounds I wrote
(6 parts available on G70 vs 4 on E-A7).
The G70 gives me the vocal harmonizer.
Also guitar mode and D-beam. And play list I use all the time.

The E-A7 gives me the pads (6 pads), sample tones, and media player.
Also nice to have the speakers for quick reference.

Most of the time I will play a rhythm with left hand bass, piano,
color sounds from EV5 pedal.(G70)..

Styles usually on the E-A7..

If I reverse the audio input from the G70 into the E-A7, I can record
both keyboards as wave files. Also monitored in the E-A7 speakers...

This is almost a perfect set up.... If Roland combines the features
of both in a new keyboard it will be a winner.