High Intensity Training - Yea or Nay?

I've never used a coach (other than as a kid), trainer (other than knee rehab and a VO2 Test) or joined a formal team preferring to go it alone and learn through reading and doing. Learning through experience, mistakes and otherwise. In '08 I bought an ultra endurance mtb training plan (which I may update in 2010) but that's about it. Competing is really about fun, meeting new friends and finding a way to burn off all of the calories. Not to mention health maintenance and probably stress reduction. Since I started racing mountain bikes in late '06, my cholesterol dropped to 166 w/o drugs or diet change. That kind of thing is nice. I don't know what it is about the erg, but I like that too. If I had the bucks I'd buy a single scull and row on the small lakes in the area too. Mountains and water. We like them both.

This post on High Intensity Training on one of the boards I read got my attention as many folks in Missoula seem to be into the High Intensity method for their clients. Particularly the VO2 Max bit of the post was of interest. I'm not too sure about it. A good debate.