The band runs VERY small.  (I had to use 2 bra band extenders to be comfortable)  But it still gets 4 stars because of literally everything else about it!  The cups fit so perfectly and are truly smooth underneath t-shirts and lightweight knits.  The support and shape are very natural with just the right curve and movement.  Overall, it is very comfortable even through a semi-active day (retail; bending, reaching, twisting).