I'm going to cross my fingers and hope someone eventually sees this, despite the fact that I don't think there's been a single post to this entire forum in months.
Army of Llamas runs some Mann versus Machine servers, yes? It obviously does, because I constantly get placed on [AoL] MvM servers through quickplay. Every time near without fail, the entire experience is horrible. There is constant amounts of ludicrous latency for anywhere from fifteen seconds to several minutes. Players drop due to timeouts and failing Steam authentication tickets. If anyone can make it past the halfway wave of a mission, it's a miracle. The server never actually crashes, though, so it stays put, to await and destroy another hopeful group of players -- usually the party that was just dropped from the very same server.
Please, fix your servers, or unregister them from quickplay.