Post testing: the boundary pits are very big and very monotonous. It made it easy to hide almost a whole base out there. From a detailing perspective, it's just dead and needs a little something-something to make it better. Perhaps you can even add an island expo out there. Just put something in there to break it up.
I like the adjacent cliff because it makes it a good place to use some interesting tactics and actually makes a colossus boundary, but I think it makes it hard to reach and reinforce your natural if it comes under attack. The rich mineral field was hard to defend for zerg, but it's two cliffs above ground, right? That could turn into an absolute killing ground for a couple of siege tanks. I think it needs a little more testing, but it's pretty good as is (especially since it cleaves the map in half.)
Good rush distance, by the way, but I think you can afford to put ramps on either side of the watchtowers instead of the farthest side.
