If ping times and jitter are really important to you, you should probably upgrade to fiber. These charts "could" indicate a change, but since ICMP packets are low priority, it could also just be that your tests have been de-prioritized.
Yes. Thats maybe whats interesting. Maybe they are doing more in-depth QoS. Some new system. That would be interesting. I was reading on another forum that a large number of gamers in phoenix are having trouble with some type of things like chat systems going offline. It started the day Phoenix switched on this new stuff. Very odd. But maybe its just coincidence. They did figure out its only effecting Cox customers, in certian areas of Phoenix. Gaming works fine, web works fine, but specifically Steam chat is going offline and coming right back online. Like its getting a low QoS priority. I think this is not related tho. But maybe..
Well there will be things to work out with any new deployment.