I own a Medela Freestyle and with my first child used the straps that came with the pump and just my own Bravado nursing bras.  Worked fine, and it seemed easier to me than strapping on another item, so I never used a pumping bra.

With kid number 2 I was plagued with plugged ducts that were painful and caused problems with my milk supply.  A lactation consultant told me that the Freestyle was known for causing plugged ducts, and recommended this pumping bra, along with larger horns for the pump.  Once I got used to the pumping bra, I was so glad I switched.  Yes, it was a little bit of a pain to have to strap on another piece of clothing, but it was a lot more comfortable, and it wasn't much more trouble than strapping on all the plastic straps that came with the Freestyle.  And it was really really secure, and actually I saw a lot less accidental leaking than without the bra.

I bought the light pink color to better hide stains.  I kept one at home and one in my desk drawer at work.  I wear a size 8/10 but the smallest size (XS/S/M) worked well for me, it is very adjustable product.  I would highly recommend this to all pumping moms.