I used to have tunze230/3 on my older 108 Gal.
it was very quiet, easy to clean, and had an ozone port.
These are DOC skimmers (disolved organic carbon skimmers) and will NOT skimm particulate and plancton.
I can compare it to my ETSS (check
my pictures for the feast full of a skimmate on this monster). and you know what,? my tank was not better with ETSS. That is why when i had a chance a bought tunze 240/3 but never got to use it because i have no sump on my new tank.
So i vote for Tunze big time.
I know skimmers are very touchy subject and everyone has favorits, but for me its alwaysthe same points to consider when selecting a skimmer
1 Ammount of air mixing.
2 Quietness.
3 easyness of cleanning.
4 Power consumption.
the rest is marketing hipe like for example galon rating... gallons do not produce waiste right? animals do.
HTH
~~~