The rocks will be green/black in no time and soon you will be cursing the algea that is making your clean rocks look dirty
Personally i dont like either, they look too "placed" and artificial, especially with the center pieces placed dead center of the tank. Sorry.
A few tips for a more natural looking tank
Always place rocks and wood directly onto the base of the tank and add the substrate around them, not only does it look better but it give more stability to heavy pieces that could topple and damage the tank/fish and means less debrie can get trapped under the decore and spoil water quality.
When setting out the aquascape imagine the tank divided into 5 equal sections along its length. Start your design with the center piece in the second section in from the right hand side of the tank and then work outwards from there, for most people the line of sight automatically skews off slightly to this side so it makes the view more comfortable and natural feeling.
If you are adding plants add them last and try to place them as they would appear in nature growing out from under rocks/wood etc where the shelter the object has given would have allowed the young plant to take root and grow, you rarely see plants in open spaces in the wild.
