Buying a Dishwasher - What is a RO unit?

What is an RO unit? (Reverse Osmosis) and do you really need one?

What is an RO unit? (Reverse Osmosis) and do you really need one?
When browsing dishwashers you will find that a RO unit is offered at an additional charge or is ideally already built into the machine. Do you pay the extra or opt out? 

Reverse Osmosis is a water treatment process that eliminates 98% of minerals, bacteria and impurities from the water (Hard Water) creating 'soft water'. It is not recommended to drink this water as is also removes good minerals and bacteria, on the other hand when using this water treatment in relation to a dishwasher you may be surprised of the benefits.  Not only do dishes, glassware and cutlery come out streak free and shinier without any added rinse aids or extra effort on the staff’s behalf. Your dishwashers overall machine life may even be extended longer! This is due to the minimization of lime scale and mineral deposits created in the machines Mechanisms and spray arms especially metal components.  

In conclusion you don’t need an RO unit as far as hygiene is concerned as commercial dishwashers must reach a minimum of 80°c to meet Australian standards. However if machine health and longevity is a priority then a RO unit is recommended.