I followed the recommended guidance and went down a band size and up a cup size - this worked out perfectly. The straps and band are soft, and dig free. No lines are visible beneath clothing. If it weren't for the underwire I would forget that I was wearing a bra (of course the underwire is a necessary evil for support). The straps do occasionally slip, but I have slanted shoulders and even adjustable straps tend to slip on me.
I have spent too long wearing only Victoria's Secret bras and I'm so happy I've converted! This smooths the lines I got used to seeing on my back and shoulders and even after a long day of work the underwire doesn't bother me. I've ordered both colors.