Is it better to go to class, or watch the recorded lectures? I'm in a large class where lectures are recorded and posted online.  The lectures are difficult enough that I benefit a lot from being able to pause the videos and stare at the slides for a few seconds, or even rewind the video if I realize I missed something from an earlier part of the lecture.  It's also nice to be able to pause the video if my mind starts wandering, so I can give the lecture my full attention.

However, if I don't go to class, it's easy to get behind on the lectures, and it's easy to get distracted while watching the videos (so watching a lecture online takes me a lot more time than I would have spent in class).  What do you think is the best approach?

If it makes a difference, it's my advisor's class, and the lectures are at 9 am.
A combination may be best. Go to the lectures. During the lecture, if you miss something, or have trouble understanding, make a note of the time. Afterwards, before attempting the coursework, bring up the recorded lecture and view the places you missed during the live lecture.

That way, you get the keep-on-track benefit of the live lectures. You spend your viewing time in a very focused mode, looking only at the difficult parts of the lecture, which may reduce the tendency to get distracted.