Biased in which direction?
Less of an overt political bias, more the habit of Kuenssberg, and others to ask "Gotcha" questions or set elephant traps. Same friends comment favourably about the Science and Medical correspondents. The political correspondents are more interested in the next soundbite on the Rolling news whereas the Science/Medical journos focus on understanding and explaining the Science.
As I said, same sort of comments from friends across the political spectrum.