I have been using it for about a year now and have had some great success as well as a few failures, it has never damaged any batteries but if a battery is damaged or shorted it will not fix it, but does a great job on trucks that have been improperly chargered.
we use it a lot on our rental fleet as a maintenance as well as used equipment that comes in, we have tried selling it as a service but usally by the time a customer has a need for it it is too late for the battery. As far as the Battery manufactures go they would be shooting themselves in the foot to endorse such a service. All it is is a battery desulfator, nothing more. it just takes the place of proper charging.