Im very happy with this - I have 2 of them.  I believe it is to size, possible runs a bit small.  I felt the wire was a bit pokey until I'd worn it a couple of times - now no problems.  For nursing, the fabric is a bit stiff so you have to kind of bunch it up to get it out of baby's way.  This is the first nursing bra since I had a baby that actually makes me feel like I have a nice chest again!