Actually, that Sota unit is as good as air-fed ozonators get. Sota has undergone several revisions of their product to get to where this one is today. Just bear in mind that all air-fed ozonators will produce NoX if the air has any humidity in it at all. The only way to avoid NoX is to use pure oxygen as a feed gas for the ozonator or use a very good air dryer to dry the room air.
Hope this helps,