I gotta say that I've been quite impressed with Century Link's HSI since I signed up with them almost a year ago. I get consistent strong coverage and have never had a single outage/ downtime to this point. My cox HSI which I used to have before constantly dropped coverage and was almost down everyday around midnight for ''maintenance''. Of course location probably has something to do with it. I live around 19th ave and northern.
The best that Century Link will offer me is 12 Mbps. Below is what I am getting from Cox. I have not experienced the problems that you describe. I am near 7th Ave and Thomas.