Double breasted is better for flashing. The wrap keeps you warmer.
Well, I will admit I have owned lower quality ones in the past and have always ended up selling them on ebay. I love the functionality and the fact that I can keep more of a crease in my trousers when wearing one, but the issue is when it rains and I am out walking in a trench I sweat profusely so the feeling of being in one is horrible. I am just getting so sick of soggy trousers I might have to yet again, suck it up and pull the trigger on one.