I spent 3 hours upgrading from PD3 to PD4 in my MBP early 2008 this morning. I started with a My-Boot-Camp VM created by PD3 and installed PD4. The conversion of PD3 VM to PD4 version was smooth but slow. When the conversion is done, I launched My-Boot-Camp VM again and Parallels tool was installed very slowly and stop a few times when couple of found-new-hardware windows pop up and stay forever. I rebooted the VM and same thing happened, Parallels tool never installed completely. I then remove the My-Boot-Camp VM and create a new one with custom option. But again, parallels tool never installed completely and stops in the middle. Finally I deleted the VM again and boot the machine natively in WinXP via bootcamp and remove parallel tool, and then boot into OSX and set up a fresh new VM again, and boom! parallels tool install correctly and everything seems to work nicely. But now I really don't feel the 50% increase in speed/performance. Everything seems slower than PD3 build 5626, even with 2 processors and 1500MB RAM allocated. VM boot up, software launch are obviously slower. Anyone notice PD4 is faster than PD3?