I wore a singlet and leggings (I'm a prude lol)...eventually the knickers and leggings had to come off but I had my bra and singlet on the whole time. The midwife and my doula had a bit of a time getting my bra off for skin to skin.

That dress thing could be good for early labour I think. Could get annoying later on though. As Teagz said it does look a bit 'nice'. Would make an awesome breastfeeding dress though.