they are about the same as petrol & diesel are the same.
U/m is a blend of various detergents designed to detach & encapsulate soils ready to be removed, acid rinse is a solution designed to rinse out soil that has been detached from a fibre with an appropriate pre spray and leave the carpet in a neutral Ph condition.
to go back to old school cleaning.... if you want to use the acid rinse you first need to precondition the carpet with traffic lane cleaner and a good scrub then use the acid rinse in your machine to rinse out the dirt
acid rinse by its self has very little cleaning ability