The other forum is sponsored by Solutions, so there's your reason for the promotion of M Power etc.
Have to say that M Power is great for jobs where the carpets are in good condition, but I find it doesn't really cut the mustard for anything more than minor soiling. Tried using it on a fairly minging carpet the other day and it failed miserably even hot and mixed at 80:1.
I use products from several different manufacturers Prochem, Solutions, Craftex etc. It's horses for courses I guess.