@itsmedavid, Thanks for answering that; you beat me to it. I can view the community but I cannot post anything when I am at the office. My responses have to wait until I am home.
System Mode MANUAL means that you control the Particle cloud connection and the WiFi connection manually. The default is no connection on startup.
 SEMIAUTOMATIC means that processing is automatic once connected to the Cloud (and WiFi is connected). The default is not to connect until your application commands it.
AUTOMATIC means that the default behaviour is to automatically attempt to connect, which means it will not get around to running the application when there is no connection established.
 Along with this, there is some functionality during the connection process that is blocking (it blocks the rest of the application thread). There is a good discussion on it here: