I use my ghillie when I snipe, I once forgot it, and stuck out like a guy wearing UCP in the jungle (quite literally as I wear ACUs when not sniping), I will only wear my ACU when I snipe in an urban environment or when I play CQB. Like mccl said, its about your play style, but I also believe it's about personal preference - I personally love waiting for that perfect shot, and I love the look and feel of a ghillie. I also believe it's about where you'll be playing the most - don't use a ghillie in urban AOs and DON'T use UCP for jungle/tall grasses.