JKD videos

Do the instructional videos from the JKD official website teach well? I have 3 years experience in karate and 3 years experience in TKD. The problem with them is, the only time I can fight is if the other person is using TKD or karate. It's just not practical and its going to end up with me hurting. Does JKD work well in all around fighting? Should I get a mix of different martial arts like Aikido or Judo?