The Medela Swing Maxi is the updated and lighter replacement to Medela's very popular PISA pump. It is similar to the Swing Pump - but it is for dual pumping. My very first pump was a Medela Swing pump but I decided to sell it and switched to a dual pump. The Swing Maxi is a definite improvement over the PISA by being more portable, lighter and easier to carry around.
The main come-on for me would be the price - at P13,500, it is the most affordable pump among Medela's line of electric pumps that come with the 2-phase expression technology. I currently use the Freestyle (Review of the Freestyle here) and here are advantages that I feel the Freestyle has over the Swing Maxi:
Size. From the photo, you can see that the Freestyle is a bit smaller than the Swing Maxi.
Digital Timer/Display. This is the major advantage that the Freestyle has over the Swing Maxi. Since the Freestyle has a built-in timer, once I hook myself up, I forget that I am pumping, I am free to focus on other things. With the Swing Maxi, you have to keep your eye on the time to make sure that you don't over-pump. You can also see the level of suction/power you are currently on with the Freestyle. With the Swing Maxi, since there is no digital display, so you have to go by feel on how strong you have adjusted the suction/power.
Accessories. The Freestyle comes with carry tote, cooler bag with 2 extra bottles plus freezing element. None is included with the Swing Maxi.
Memory. On the Freestyle, you can program your last pump setting. However, this is something that I don't really use so I don't really consider this as an advantage over the Swing Maxi.
Batteries. The Freestyle comes with rechargeable batteries. The Swing Maxi can be powered by 6 AAA batteries. You can purchase rechargeable AAA batteries if you find yourself relying on the battery power of your Swing Maxi to prevent expense/wastage.
That said, I'm happy that Medela Switzerland has come up with a cheaper and more affordable pump with the dual-phase expression technology. So if you have the budget, go for the Freestyle but otherwise, the Swing Maxi is good enough.