Listening to YouTube comparison videos is clearly of limited utility. That is not to say that it might be possible to hear differences between two systems playing the same music, four example, but obviously cannot be relied upon for a buying decision. It does give you an opportunity to listen to some very high end equipment that you would never see outside of a show. It is obviously no substitute for actually listening to equipment, and I would be surprised if one could hear anything but the most obvious differences, if that, such as differences between high end speakers.
