I have the same model and it worked flawlessly until i upgrade my connection speed with my ISP to 100/20 mbps and about every 6 hours it would freak out and just stop working. Before the upgrade with the isp my connection was 30/10 and like i said worked great. I tried stock and merlin fw rechecked all my settings and i could not get it to work for more than 6 hours without crapping out on me. Now i have replaced it with a draytek vigor 2130 that was sitting on the shelf as a backup and my connection has never dropped since, i do have a large network setup or maybe a medium setup with about with around 20 devices. the rt-ac66u just couldn't seems to handle it, maybe the other models might do the trick.