if it works go for it
you will get good results from most systems as long as they are maintained
exactly so its a waste of money to buy a ppb system IMO.in fact id go as far as to say once you have a good secured tank in your vehicle the rest is very simple,hose reel, pump,etc...even fitting a gas heater is so so simple saving yourself thousands of pounds.
im lucky as DI only is all i need(tap tds 29) so no need to mess about with an RO.thank God.