Connection Delays, packet errors in online games and several times I had the router decide not display any pages, just browsing and not changing anything, until I rebooted it. As for QoS, I turned off everything, no change, then enabled it with max 2M upload. Connection delays were cut in half but online games still having connection quality errors. No more testing is necessary, when you can't get into the router interface then something is definitely wrong with it. Went back to my 4500 and everything runs perfectly again. I'm going to RMA this unit.