RCN (Boston area) over-compressing HD channels?

I have a TiVo Roamio with service from RCN Boston (it is my own TiVo, not an RCN-branded TiVo; I owned it before switching to RCN).

In the past couple of weeks, I have noticed that the HD video quality of many cable channels has decreased significantly - loss of detail, general mushiness, people looking waxy. The channels in no way look "high definition."

So I checked how much disk space the shows being recorded were taking up: 1.5 - 2 GB per hour for an 1080i MPEG-2 stream (or, in the...

RCN (Boston area) over-compressing HD channels?

RCN (Boston area) over-compressing HD channels?