I got VIPRed a year ago from a connecting flight to a nonstop flight because DL thought I missed the first segment when I actually made it. Arriving to LHR and finding out that my reservation was rebooked to CDG-JFK nonstop was a nasty surprise. Eventually I got a phone agent to restore my old itinerary so I could board my LHR-JFK flight.
I was worried about my bag. It made it to JFK but it appears that the system did not validate the barcode, as it had a new, handwritten tag with my flight info and my PNR.