[Q]

" Would you honestly rather stare at totally flat graphics instead of 3d ones if it had no impact on gameplay?"

Of course not.
But I think it is an illusion that it has no effect on gameplay!
Even with a modern computer 3D graphics will limit the maximum reasonable number of ships/units in a combat. But more important as mentionend earlier I am convinced the creation of new races will be more difficult than in SE IV. I would be very surprised (but pleased), if we get as many races as we now have in SE IV.
So the question is simply is the 3D effort worth it?
I don't know yet but I will see and buy the game as soon as possible.