Has anyone used the DSC BV500GB ceiling mount PIR and glass break detector? Is there any reason to not use a ceiling mount over a corner mount in a residential environment? Is there a reason to not have a combined unit if you need both functions, or is it much better to have separate units? This seems like the most cost effective (both from purchasing and wiring in retrofit) way to go. Also, do you see any issue with this on a vaulted/cathedral/sloped ceiling?