I have been using Challengers for close to 10 years now, after 2 or 3 years of struggling with my first full size orbital machine, the Oreck LowBoy. In all that time, I have never had a customer call me back and complain that her carpet fibers looked different in any way (except cleaner!!) than before I had cleaned them. So I don't feel that this is any kind of issue that should cause you concern. I use the holy glider for most of my work, but if you feel safer, then by all means use the middle, solid glider. I don't ever use the thicker of the 2 solid gliders. I think it moves the pad too far above the carpet to do much effective cleaning.
Some newer, never before cleaned carpeting will shed some fuzz when first cleaned. To wrap up your job, just vacuum this up at the end of doing that particular room. My Kenmore Progressive vacuum cleaner seems able to vacuum on damp carpeting without clogging (yet!) It is also Consumer Report's best Pet Hair Remover of all the vacs that they test every year.

Mark, thanks I do not expect this to be a problem, I am going to clean another section of my carpet today and use one of the other gliders. I am sure it will do the job without causing any fraying. Wether or not the carpet I cleaned already has some fraying caused by using the holy glider I am not 100% sure. It could just be some wear that has naturally progressed over time. Anyhoo thanks for your input................Sam