Hi Stefan,
I have used it a few times now and was it does seem to clean pretty well.  I am not afraid to use it on all but heavily stained nylon carpets.  As to how well the protector part of it works, it's hard to tell.  I don't have much to compare it to.  I did use it on the upstairs of my home and it seemed to work ok.  As a protector I think you are getting less of the protector part but quite a bit of the acid dye blockers for stain resistance.  It does have a full protector in it I am told, but much of it is removed during cleaning.  I still think it's a good value to customers if sold for about half the price of a full strength spray on protector.  It has a pretty strong strawberry type fragrance.  A bit too strong for me, but not a horrible scent. 

As far as the steamin demon I have had it close to a year now.  I don't use it much, but have liked it for one account I have and have liked using it on some urine jobs.  I would prefer to have a CA for all but the one commercial account I use it on.  I'm trying to figure out my longer term strategy for my equipment.  I may just get a Kwik Steam at some point and keep that on the van all the time and just keep the SD for the one account I use it for.