Well the deal is... Medela is phasing out the PIS. They only carry the original in a shoulder bag now.. not in the Backpack any longer. The PISA is comparable to the symphony. Just much more affordable. It does only have one speed but has the let down switch. But you can control the suction. I went ahead and got the PISA since the original is being fazed out. Also with the Advanced you can take the pump motor out itself and use very little space. The original you have to have the big bag in the way. The motor does not come out. I picked my Advanced up on ebay for 130.00 Half the price of a new one. And it was only used 2 times. So its really up to you. They are both good pumps