NETGEAR C6300 Cable Modem Router AC1750 (Open Box)

We have Cox internet service. We had some trouble hooking it up, which ended up being a cox problem. The lady put the MAC address in the serial number spot. either way we had to call Netgear for support. After 25 min on the phone my wife was told we had to sign up for a level 6 tech support to help us any further. The cost was a 150 $ for a 2 year service contract with them for us to take the support any further. After telling the technician that she would have to think about it, he abruptly hung up on her, without even a good by or a thank you for calling. I include this in my review because I want people to know the quality of the netgear support, RUDE. like I mentioned though, it ended up being a Cox problem. Once we got the modem-router working, it was the slowest modem I have ever experienced. We have 300 MPS service but the modem ran so slow it reminded me of an old dial up connection. It couldn't even run one device without buffering every 2 minutes. I dont know if it was because it was refurbished or not. I know one thing, we were not about to call Netgear tech support again to see what the problem was. We will be returning this unit and not purchasing any of their products any more and I will be recommending the same to my friends and family as well.