Trenton, I definately agree with the crop on the new city portion, its out of place. What do you mean about the "feared '50/50' composition". If its about having the Acropolis smack in the middle, then I think that the city crop would actually center it even more. I kinda like the clouds at the top, even though they remind me of the Simpsons. I would have to lose them completely. To get the Acropolis out of the center I think I would have to crop out almost all of the sky, leaving about only 1 inch.
As a side note 4 & 5 were taken from the same place, just in a different direction, and a couple of minutes apart. I think if I could mod the picks such that the sky in 5 would be more like the one in 4, then 5 would be my fav. As it stands, untouched, number 4 is the one for me.
Thanks for the comments