I wasn't a fan of the tops I bought. Sure, they looked cute but they were awkward. Half the time, I couldn't pull my boob out fast enough for E. He would get mad and a screaming baby doesn't help a flustered mom. I'm pretty sure it drew more attention than me nursing him. Now that we're NIP experts (or something like that), I layer with cheap camisoles or Undercover Mama camisoles. The Undercover Mamas are awesome and by far worth every penny. I can wear them with every shirt I wore pre-pregnancy and they work with my nursing bras.
So there you have it. I don't think nursing tops are necessary. Plus, I was over empire tops after wearing them for nine months!