It Looks a bit boring, but that is a very good thing. Seems to be a really solid layout! Only change I would like to suggest is wider ramps at third next to main which face at opposing third next to main. It is only a double wide ramp right now, isn't it?
This is almost gauranteed to give each player the half of their map. I can't fathom why I would ever want to expand on the far away bases on my opponent's side of the map >.< The mains need to be smaller though.