63ms is fantesticle ping from canada down to vault networks in florida. the ping spikes in siege im guessing are from congestion caused by...well, siege. im guessing (guess may even be an overstatement) that the proxy offloads you to the server and coordinates syncing it and the chat servers...and in siege you're still on your server but "proxied" to the siege server. total guess
wireshark it and see....or at least tracert the server in and out of siege. not that you can change the routing unless you use a ping smoother service or vpn that offloads in florida, but it will show the problem area. if it doesnt then the problem likely resides behind the proxy in the rom server cluster.
i had 25/25 fiber on a backbone in DC for like 8 years from work. ping was constant ~55, never changed. now on dialup in redneck afghanistan im lucky to get below 500, not even taking into account the constant spiking >< be happy you have any broadband available
checking the internet weather map also may explain intermittent spiking...bad major router or a detoured route due to line work at a major node etc
the 160gb cap blows at that speed though..hell i sometimes would blow through 15tb in a month since my fiber also fed HD cable/ppv movies etc.
oh and pr0n..only a tiny bit though