The Ken Roberts course has some very dangerous trading tactics. The whole inverse pyramid trading for instance, cost me in the mid 30k when I was using his course back in the mid 90s. I had corn contract pyramided to the high heavens. Then a relatively small pull back took the entire stack down in about 20 minutes.
If I knew then, what I know now, the impending doom was obvious. After that I went and took trading courses at the Merc, and the CBOT following many years of paper trading while I tried to re fund my account.
I actually ended up with a pretty good system, which I wrote a course manual on. You can find info on it at www.factstrading.com It has a whole section devoted to dangerous practices to avoid.