I did find that a daisy chained zwave bulb behind a zwave outlet was turned off almost all the time. it's right next to the hub so might be used in many of the routes. with the bulb powered off the mesh, my suspicion is that it was causing issues with routing. i now keep the outlet on at all times to make sure the bulb remains on the mesh. either i got lucky, or this helped. the performance and reliability is up. any thoughts on this reasoning?
i have the mouser usb stick coming today so i'll remove those ghosts. hopefully all will be resolved then.