I have TC 1GB which is connected to the Internet via PPPoE. When I ping any web-server, there are a lot of packet drops (40%-60%). WiFi signal strength is good, ping to TC itself have no packet loss at all. No walls, TC is in direct visibility.
It seems that TC inserts some kind of lag when my MacBook Pro (or iPhone/iPad) tries to establish a TCP connection. Once connection established, traffic is fast. (I have tried to route all traffic through VPN and pings are non-lossy in this case; also torrents are fast too).
When I connect my laptop directly to ISP's ethernet, there's no lag when I do ping (no VPN).
I have tried to reset TC, to downgrade firmware - nothing helps.