Most steam vapors cleaners [http://vaporscleaners.wordpress.com/2010/11/23/clean-and-get-out-those-chewing-gums-with-a-vapors-cleaners/] produces vapor that has less than 5% of moisture which are great to preserve and prevent the built up of mold that can damage any property. The mist ejected from steam cleaner has temperatures reaching up to 150C and is really hot and effective to sanitize the area and kill germs. Many steam cleaners come with single tank and if you have larger area to clean then choose something like ladybug xlt which has double tank and cleans very effectively and no need to repeatedly refill.
Make sure the steam cleaner has canister wheels which you can use to move around and mobilize easily as you do not want to be carrying them around as they are very heavy. When a steam cleaner is purchased they come with an assortment of attachments like brushes and metal nozzles. Make sure they are made of stainless steel as cheap metal can rust and you can loose your investment easily. Steamer Cleaners do not come cheap and are expensive compared to vacuum cleaners so make sure there is warranty of at least 3 years to cover your investment just in case it breaks down. Lastly make sure you read the reviews and understand if it fits for your purpose or need and one last great thing about steam cleaners is that they are very healthy to use compared to vacuum cleaners as they do not create dust which is an allergen.