For standard WPF 4.5 desktop application project that use PRISM on Windows 7, XDesProc.exe creates ridiculous delays that kill productivity for everone on my team. We have set up VS 2012 to open XAML files with the XML editor only to avoid this problem. However, if I try to use the XAML designer, the usual message comes up that imforms us that we can still use VS while another process takes care of rendering. However, once rendered, delays will occur when trying to type in the XAML text editor in XAML text/designer split view. To get around the delay I can kill the XDesProc.exe process in the Windows Task Manager. I miss having the convenience of the designer though. Its too frustrating to use though as the delays are horrific!