Hi All, i got upgraded from 800mbpsto 1GBps & was given black modem/router, which I honestly regretted this decision. The 5GHz performance and reliability has been worse than previous setup. I have to change to 2.4Ghz everytime upstairs to get Internet to work. I still have old modem & router, if I change back to old setup, is it plug & play or need much configuration?