Mentzer, Levrone and Ruhl are hardly individuals the genetically typical trainee should be emulating in their training. I have know doubt they know what works for them but I question whether or not they know anything about what will work for the average joe.
There are alot of articles on this site that explain the problems with training to failure. These articles are written by people who have backrounds in excersise science and years of experience training not only themselves but numerous clients with different bodytypes and abilities. I think this backround makes them the better source of informmation, and they all seem to agree that for most of us training to failure is not a good idea.
Check out Coach Staleys site for an article on HIT it may answer alot of specific questions you have.
I am stuck in an airport right now waiting for a flight.....so sorry if this sounds like a rant its not meant to be.....I am just bored as fuck.