Hmm... I wonder if something is configured differently in your area. You might even want to check the connection without a router. We have very consistent response times although I will say ping times have gone up since I switched to a D3 modem by about 2ms.
Running a simple ping for a minute from a command prompt shows min 6, max 22, and average of 8.
I'm not sure if I would agree with how the testing is being done though. An average would definitely be a good thing to have when looking at the numbers. If you have 9 packets that make it there in 10ms and one that is at 100, it doesn't necessarily equate to bad performance.