That server handles a TON of local island traffic and is really a tough server to consistently game on.
What I did was (and this worked beautifully) Deny the surrounding Miami Peer/Dedicated servers and force either a Georgia, Missouri, or Illinois server every game, instead. If you traceroute your ISP hops, to their source - then place your Geo-Filter location to the end of your trace you'll notice a more fluid connection. Give it a try.
It may take you longer to search for a match, but it's entirely worth it.