No two tanks are alike, due to rock placement, rock size/shape, how water flows around rocks, coral placement, etc. I would experiment with placement of the 40s. I actually like yours on the back wall, they kinda blend in. Maybe spread them out or move them up an inch or so, particularly the lower one.
I like the two smaller 40s vice the one large 60. Allows you more flexibility and redundancy in case of one fails.
Tank looks great.