I have been running my 180g planted dirt bottom gravel capped tank for about 5 months now. The EC40 is, of course, a central element of the filtration system.
On initial startup of the tank the EC40 was the only mechanical filtration I had and the initial charge of DE lasted about 3 months before it had to be changed (knocking it off and recoating the filter screens was no longer effective for more than a day). I drained, disconnected and moved the EC40 out side. When I removed the top of the filter what I found was MUD! All the dirt floating in the water column of a freshly started dirt bottom 180g tank was caught by the DE. On the plus side when I initially turned the filter on the water cleared up in a couple of hours to crystal clear... which is pretty incredibly since I have a mix of potting soil, fine volcanic soil, activated charcoal (as a buffer), red clay and several other nutrient enhancers... and like I said this was without any prefilter.
After the water change I have been pretty lazy (working on other aspects of the tank) and I still do not have any pre-filtering. For the last two months I have been recharging (knock off the DE from the tubes and allowing it to recoat) every two weeks or so.
I still love the EC40 and would not want to run a tank without one. OK, we have 3 other tanks that run HOB, canister or built in filters and they all take tons more maintenance than the 180g with the EC40... but those are my daughters pea puffer, Axolotl and goldfish tanks so she gets to do the work! Well a lot of the work on her tanks at least.
(Before starting up the tank.)