We got an ACT connection two years back and recently moved away from it due to several issues.
The most frequent one is the disconnections due to unknown issues. It just seemed frustrating that the internet link was down for a cumulative time of a week or more in a month. We found our cellular data to be way more reliable than ACTs fiber internet.
Adding to the woes, the customer service needs some serious improvements. Most of the times, the customer service will close your service request without even verifying your request was addressed. Most of the time, you end up creating multiple requests hoping they fix the issue.
The problem doesnt end there. Disconnection of your internet also needs several phone calls to push them to get your internet disconnected and update your bill to make sure you are not over-charged.