The PISA is sort of known as one of the main workhorse pumps. It's a dual pump, so if you're more coordinated than I am (this shouldn't be tough), you can pump both sides at the same time. It has two speed settings - when you first begin pumping, it is a faster/harder suction to accommodate the initial letdown. Then, after about two minutes, it slows down. I ended up needing to press the button to go back to the first setting usually just to work with my particular needs, so I sort of wished at the time that it didn't automatically change the suction setting, but I think that would be a bonus to people with more standard needs.
With the pump, you get the following items (or at least you did 3.5 years ago) - cooler bag with ice pack, standard-sized flanges and connectors, tubing, an AC adapter unit for mobile use, and four Medela bottles. Mine also came with a little sample of a few milk bags, and some Medela lanolin. We didn't want to have to completely wash all bottles every single evening - since I was pumping multiple times a day at work and even more at home, this meant that we needed about 8 extra bottles. The bottles have come down in price since then; at the time, this meant about $15 for three extra bottles. I also needed a different sized flange. Once I figured out the best system, it worked great. Our daughter had a small mouth, so we pumped around the clock for the first few months - other than the fact that I felt like the pump was talking to me during the middle of the night pumping sessions on zero sleep, it worked really well despite all of the rigorous use I put it through with round-the-clock pumping.
I got my pump in July of 2010 - it worked great for about a year, and then the motor burnt out. This was part of a big group of pumps that had this issue during that time frame, so I was able to contact Medela and get a new one sent out immediately. Their customer service was great - they express sent me the new one and prepaid shipping packaging, so all I had to do was box up the old pump and send it back.
I'll be using the same pump with our upcoming arrival. I don't see any reason to change - the only reason I might have considered changing would be to get a hospital-grade pump, but I think those are much more expensive. This one works great for the cost.