It's interesting that you post this, as I just had yet another issue with CLink DSL this morning. Woke up and the connection had been lost since around midnight. Multiple resets of the modem and it didn't come back, it was back up and running when I got home from work, thankfully.
I think their service reliability kind of depends on where you're at. When we were in Ames, it was fine, didn't experience many outages and the speed was OK. Here in a new residential development in Clive/Urbandale, the fastest speed they can get me is about 3mbps, even though they had told me it would be 7mbps when I was signing up for it prior to them making the connection. I contacted them to inquire about what they were going to do for me since they are only providing half the speed they sold me, they basically told me to get bent.
The speed in the evening is terribly slow, and the outages are frequent. Anytime it rains, the service will go out, no matter what. In fact, it will usually go out whenever there is rain or storms within about 20 miles west of here. I will be paying the extra fee and going with Mediacom cable internet as soon as this 12 month contract is up......only 5 months left. I had Mediacom for 7 years at our previous house and only had a handful of outages in that entire time.