We have been using Charter for close to 2 years now. The experience has been rather uneventful. I just wish we had FiOS.
-- Update --
We have moved and are no longer customers of Charter. Overall it was not a bad experience. I had some billing troubles but they were resolved with one phone call. Unfortunately that phone call was a difficult one - I couldn't understand her as her accent was very thick - but she did resolve my issue.
Charter is not available in my area, now. Verizon and TWC are my choices and I opted to try out Verizon's FiOS. It is nice to have a choice.