@tek @dokuja funny story there, as I've always bought my own modem.
I got a flier in the mail saying "300Mbps service in your area" and so I called saying "Why don't I have 300Mbps then?!?!" fully expecting the answer to be that it wasn't *really* in my area. The reply was that my modem was too old.
Fixed it quickly, and I doubt they would have upgraded it without me calling, but it was a funny challenge of my expectations.