I haven't gone back yet, but I probably won't. The nursing bras are generally thin cotton, which is great at home and out. But in the office, where it's cold...ummm... you get the picture.
I pretty much always wear nursing bras. I have one from VS that is almost identical to my regular VS Angels bras, only it unhooks from the top... so I wear that one under thinner tops, and since it's getting cool, I often wear thicker sweaters, so the "cold" factor doesn't matter that much. But it's much easier to pump and bf in a nursing bra.
Re: wearing nursing bras?
I wore my nursing bras the entire 14 months I nursed and pumped. My regular bras were no longer the correct size.
I had to wear nursing pads to work just in case, which took care of the 'cold' factor.