Even though I pretty much think the Spy is out, I would still say the Petrol. The color is absolutely fabulous, the bag is fantastic, I still enjoy toting mine around. I don't think you would ever regret it. Also, I think the Petrol will definitely retain value better too.
I like the look of the Ramona, but the heaviness of the bag puts me off. It's silly cos the size of the bag is supposed to allow me to lug more things around, but the bag weighs more than the things I lug around. I will go with the spy anyday.