Why is it that every version of Adobe Reader or whatever it’s called these day seems to get slower and slower without giving you any value added features? Real features that would make the average business user turns round and complaints when you install version 4 instead of version 7. It just doesn’t happened!
Looking at the EULA I think it’s okay to use in a business environment.
So when your machine is crawling when it open’s a PDF next time, uninstall Adobe and install Foxit Reader.