I was using Medela PIS for my 1st boy. The letdown is good, is fast and quiet, and is for heavy usuage.
A good breastpump will helps alot in breastfeeding. You may need that to help to stimulate the milk flow for the initial period.
At night, when you need to express, u need something that can do the job fast, so that you can sleep. Even when you are back to work, you also need to express fast and get back to work. Also the machine have to be quiet, so that will not disturb your baby or hubby. PIS is definately up to the mark!