I may have experienced the biggest change in ping, from 30s to 130s since I moved between continents while the server only moved to Chicago. But I think comparing the new server to my gameplay from a year ago before I came to the US would give a better comparison.
I'm playing on a laptop, and I always had to keep both the charging cable and the Ethernet cable connected, or else I would get constant CIs that made the game unplayable for me. With the new server, I tried playing using WiFi only, and I rarely get any CIs now. Unplugging the charging cable and the Ethernet cable still affects my gameplay, but on the old server I wouldn't even be able to move when doing that, and now I can play with only slight stuttering doing so. I already had CoD4x installed on my computer and had played on other CoD4x servers before, and I would still experience the same problem there, but not on the new server.
While I was fully connected with the cables and only getting CIs once in a while, people on the old server would still often tell me that I was lagging and that bullets were going through me even though I wouldn't feel the lag on my end. Maybe some people could tell me if they still feel the same after I shoot them now.
I'm not very knowledgeable about tech, and I'm sure many of you here could explain the effects of using these cables, but I wanted to share my experience to appreciate whatever changes @iboomboom made indeed improved the gameplay for me, and I trust everything else will continue to improve.
I'm still jet-lagged after a trip that took about 24 hours with layovers, so I might be imagining all of this, and if so, please don't mind me and I'll update my experience later on.