The Sony PD-150 is a pro version of the VX2000. In many ways it is the same camera, but it has some differences. Here is the list of the differences:
http://www.dvinfo.net/sony/skinny.php

These two cameras have a quite big price difference. I was asking advices of some pro people before I bought the camera about which camera should I buy and they all said, buy the VX2000 and spend the money you saved to some other AV stuff and you will get much better results that way. For example the DVCAM format is mostly politics (I hope you understand what I mean). With MiniDV you get the same quality if you use good quality casettes. With these formats Sony only wants to separate their consumer and pro stuff. It is completly different thing compared to JVC for example. JVCs consumer cameras are MiniDV and their expensive pro cameras have the same format.