Yeah, I have an pcv-rx755, and the only thing i can upgrade is the memory, processor, and the harddrive. THe mother boards are made by Asus and are made specifically for Sony, which mean that you cannot just purchase any PSU that you want. Plus, the cases are made so that the PSU, for example, is a smaller size than a normal PSU and if you need a new one, you need to order it though sony. In other words, IMO i would not buy a Vaio if you are thinking you're going to upgrade, cause it's really impossible.