I had the opposite situation.
I moved from Cablevision's NY systems, which were quite advanced to St. Louis and had to settle for Charter. Besides poor installation that had to be redone, and outright lying, there was very little HD, slow internet and worse. It was a definite step way down. After they ddi some work in the area, my internet kept going out every 45 minutes or so (this was even before streaming). This was 2005 and 2006. Ironically the then VP HR for Charter, lived in my complex, though that is a role that is extremely temporary with that company. After lots of investigation, digging and more, they were incapable of finding the issue. I finally threw them out for DirecTV and ATT internet (slow but at least reliable). Horrendous experience and biases me against Charter today. Note I also moved away several years later back to Cablevision territory, which has gone down hill since Altice purchased it. What it does mean there is no more speculation that Charter will purchase Altice at this point. Their only partner seems to be Comcast, which in NJ would make a lot of sense since Charter's area is very limited right along the river.