Has there been any discussion as to why the TWC online DVR manager is so awful? All you can do is manipulate future recordings. It won't let you view a list of previous recording nor, more importantly, delete them. Cablevision, on LI, allows all of that both on a PC or smartphone.
My only guess is that TWC has more subscribers and consequently more user support calls when either the software bugs hit or someone messes things up on a pc or smartphone (which are by nature cableco unsupported). It's also likely TWC didn't spend big bucks on the DVR Manager. Alas, customer satisfaction is low on the totem pole scale.