Welcome to our forum.
I have spent the last 4 1/2 years in the maintenance dept. of a 32 million gal/day water treatment plant that uses chlorine and ozone. I have spent time at other plant that use chlorine and UV.
I had a customer with a built-in spa that had a UV system - it was a huge box with a clear pipe about four feet long. In the center of the clear pipe was an UV light bulb. As the water passed through the system, it was exposed to UV light.
As far as efficiency of ozone, you need to remember that water treatment ozone units usually (always(?)) have 100% O2 attached to it ... we breathe 21% - there's a 79% reduction in efficiency even if it is a CD unit.
Enough of the nice stuff, I would like to correct you on the UV part though. UV sterilizer do not creat ozone, to create ozone gas you need a high voltage current and oxygen. In my industry they are primarily used to treat wastewater and in oder for them to work properly the water must pass though very slowly. Once agian I apologize for the tone
Chasthis is getting very confusing yourself, Vinny and I are posting back and forth on 2 different topics. We really should stick to one. I took a quick look at the units you posted the pics of and did some quick searches on yahoo. I have to admit this may be something I am not familiar with, but learning something new is always a good thing. The beast we use for drinking water is 46,000 volts,02 extraction and can achieve a 5 ppm count. As you have said it is drasticly different. I will dig up the info I have at work on Monday and in the meantime I will snoop around the internet for the units you showed. You never know I might be able to say I learned something today!!