Hi T.-
I've never used it, but I found a website with reviews on this product that may be helpful:
http://www.epinions.com/pr-Nursing_Accessories-Whisper_We...
It sounds like a few women really liked it, but most were not too impressed. I think the main drawback for using it at work is that several of the women said it's really loud, not quiet as advertised.
Have you ever pumped before? I've been breastfeeding my first baby for 8 months now and pump occasionally. If I am "full", I can pump out the appropriate amount fairly quickly. I just use the AVENT hand pump- painless and easy to use. I don't know anything about the pump you're looking at, but if it doesn't work out... you could probably take enough breaks during your work hours to pump as needed. Like I said, if you're full, you'll probably get quite a bit out in only 5-10 minutes. If you've never pumped before, I would recommend starting to now to get used to it. The more you do it, the easier it is... and plus, if you start now you can freeze your breastmilk so that your husband or babysitter can have a ready supply of milk when you're back at work. Good luck!