now that looks more like it :D The Golds are muchh better.
is that a xel'naga tower right next to the natural? or are my eyes failing me. I cant seem to spot them in the green version visibly.
the dam idea in the middle is awesome for aesthetics. Its these kinds of stuff that make up the artistic value of melee maps. Love that bridge btw.
oh and LOS blockers, dont forget em. they change the game alot by allowing some baneling surprises and such.
My only other concern would be that huge chunk of higher ground (the one thats part of your main and is sticking out towards the second ramp from your base). Now im nowhere near pro, my highest league stats currently is platinum on 4v4. and several golds for 3v3, but that area is asking for some defensive tower/siegemode tank placements :P and has potential to fight back any ground aggression towards your natural. encourages turtling for the most part, but idk how it will turn out. Blinkstalker/Reaper/Collosi cliff abuse would definitely be a good choice in your map as you said.