[Iron Triangle]

I think it is very useful. Just as much as BJJ. In all due honesty I really don't see the difference between Traditional Jiu Jitsu and it's Brazillian counterpart (other than maybe BJJ has more ways to set up a hold than Traditional).

In fact, when I went to a Muay Thai school my sensi asked if I had any Martial Arts training; I told him TJJ and he said "good, Japanese much better for self defense than BJJ. BJJ to much of a sport. JJJ is more for self defense." His words not mine.