I have both----I pumped exclusively with my daughter even though I am a stay at home mom.
I like the Advanced better---for the first two minutes, it has a letdown feature which gets it going quicker! I think that is the major difference between the two of them. I don't know how to describe it, but I would be done pumping in 10 minutes.
The regular was given to me by a friend and I kept it at my parents house for when I was visiting them out of town. It worked well, it was a good pump, but I preferred the Advance.
I am planning to pump again with baby #2, due in January, and doing the same thing.