Cable operators seem to have finally realized that their clunky set-top boxes and user interfaces are hurting them as they increasingly compete with Silicon Valley’s slick-looking TV devices and services. Comcast CEO Brian Roberts used his annual presentation at The Cable Show, taking place this week in DC, to announce that his company will introduce a set-top box, called XI3, that’s four times faster and three times smaller than conventional boxes — and this fall will roll out an operating system, called X2, that offers “a seamless experience” to navigate a TV set and digital devices. It will provide six guides — for general listings, kids, movies, sports, personalized recommendations, and upcoming shows based on the user’s interests. Movie listings will include Rotten Tomatoes scores and TV shows in the guide will indicate the Twitter buzz measured in tweets per hour. There’ll be a button to call up the last nine channels watched. The company also added features to help about 20% of the population that has a disability. For example, visually impaired people can receive audio feedback telling them what’s going on when they push a button on the remote. The service also will accommodate spoken search commands. “It’s about personalization and getting you there faster,” Roberts says. The Comcast chief also touted his network’s broadband speed showing a 4.2 GB 4K Ultra HD video file downloaded at a rate of 3.2 GB per second over his system. “This is 300 times faster than the first demo I did at a cable show and it’s on the same network,” he says. Later today Comcast will provide the first public demonstration of U.S.-based delivery of 4K Ultra HD video which can take place over its existing network.