I personally find fighting Sun breakers to be an exhilarating experience. If they see you, and are in range, you're dead plain and simple. The only way to really kill one is not to run straight at them but skirt the edges of the map with a sniper rifle and hope you kill them before they get to you. However, I have killed one with the last word. It was difficult, and I had to reload, but I did manage to bring him down. Lots of jumping, lots of dancing. It was great!