Harness Bar vs 4 pt cage vs full cage

ENT-Z

As I continue to gain some skill during HPDE sessions, I am getting more concerned about safety since the speeds are starting to pick up considerably. I would like to add a harness system so I can use a HANS device. I know I can accomplish this with a harness bar such as the Robispec option but am wondering if there really is a big advantage of installing a 4 pt cage. I know a handful of you have them and would appreciate your input. I would think what would you would really want is door bars which of course involve a full cage. What does the 4 pt cage get you - I don't see it being that protective in a collision with a tire wall/concrete wall. Obviously it would be useful in the rare chance of a rollover. Please enlighten me!