I have the Mytee HP60 Spyder for a few years and it has been a great addition. Its small enough for a 1-man shop but still holds 3 gallons of water for both water and recovery tanks. The water is heated and pressure is just about perfect. Water lift is outstanding, and on every vehicle I use it on, no matter how clean the floor surfaces look, I always get a recovery tank full of brown to black water removed, depending on how much dirt is actually buried deep down in the carpeted surfaces. I also have the optional drying kit which uses the hot air exhaust to direct that air right back to wherever you want to point it to, while you are working, so it is helping to dry out your cleaned areas, while you are cleaning other areas.
The HP100 is the same machine, only bigger tanks, same spec's as this model.
I never use a slurry mixture so far; I just dont like to run anything but clean water past my pumps, because I think they will live longer that way, and I really like knowing that once I rinse and extract the carpets, there is nothing in the material to later attract and hold onto dirt, etc..
I pre-treat the materials with something like low foaming Meguairs APC+ brushed in and then rinsed and extracted. On really badly greased mats, sometimes that Meguiars Quick Out Carpet Stain Remover product will work too.
The idea for me is to use as little of any product including water as possible, so I have as little as possible to remove. If floor mats are really really dirty or full of sand, etc., then sometimes a good pressure washer will be faster to get all that stuff removed and then come back and extract the water..
Machine also works great to clean and extract cloth covered seats!
Dan F