The use of Ozone has been dying back in the past few years. I know lots of reefkeepers that dont use Oz at all and have gorgeous tanks. The use of Oz was typically used with the older skimmer types as an aid to help the skimmer do a better job. My feelings are this and have seen many articles from seasoned hobbyist's Delbeek,Moe Sprung that with todays skimmer technology and their efficiency that the use of oz is rather outdated. This is not to say that it is no longer of any use but when you can purchase a very effective skimmer why spend the money.
IMO, I agree with all the above. I have used it myself in the past before my big tank - and the reason I haven't used it this time is due to being able to make myself a skimmer which can do the job easily (for £30.) I also found it to be highly problematic and to be honest, it really, really is one of those things that's just more trouble than it's worth.