The last week or so I've noticed a growing problem of lag spikes where about 50-80% of the people on the server's ping jumps to 150-400ms and stays there for 30 seconds to several minutes. Sometimes this happens fairly frequently during a level, sometimes not at all.
Pretty much makes the game unplayable during these spikes, and I notice it's not everyone on the server - just most people. This leads me to believe it's a network issue with one or more peerings.
I really like your servers, playing gungame anywhere else is pretty much a yawn, but this growing lag spike problem is getting pretty frustrating.