It would be really helpful to be able to specify which render node to use and independently specify which camera to use.  Because I'm working on a project where my boss wanted two cameras at two different render qualities each.  So I ended up having to save out 4 different files in order to accomplish this.  If anything changed in the master file, I had to remember which settings to restore and then save it back out. It just became a bear to keep track of everything.  It would be much simpler to deal with if these settings were exposed to the command line.  
Also I found that if an -ox is not specified and one is still specified in the render node.  It will save one out.  If an -ox is not specified in a job submitted from the command line, it should not be saved.
I'm still working with Preview version...so if something has changed in the final version let me know.