I have used all 3. Depending on the type and level of dirt that you are facing.
Pol Star will do 90% of what you need at a ratio of 1:10, and you can increase dilution ratio. The advantage is that it smells better, and leaves some protection behind. I have a dog, we have a white rug in the living room an at 1:10 it will remove the stains the dog puts on the rug with no issues. Leaves a nice fresh smell behind,
MZR is a stronger version designed for removing soot and grease. If you are working constantly on filthy work type vans all the time this would be the better product.
Greenstar is a good all rounder and at 1:10 will remove most things and can also be used as a Pre-wash, tyre cleaner etc as its an APC.