I live in northern NJ and fly CO most of the time but continued as a NW Worldperks Silver Elite. However, after the merger, Delta has started screwing around with Worldperks and I decided to fully switch to CO. I sent them an email yesterday and got a reply this morning. I no longer have to worry about how else Delta will undermine my miles... I'm burning what I have on CO before CO leaves Skyteam and then it's a clean start.