Is there a noticable difference to use a ManagementEventWatcher or a DispatcherTimer??

Hey,

is there a difference in respect of Systemresources and timeconsumption if i use a DispactherTimer instad of a ManagementEventWatcher to overlook is there a usb drive connected or disconnected. I mean the DipatcherTimer should run the hole time, the Application is active.

Thanks...