We have already tried: Without filter, filter and foreign original filter. Whether these things now descale water and machine, I can not judge, because no professional with measuring instruments. But one thing I can confirm: The coffee tastes with the original filters best! Although they are expensive pork, but apparently worth the money.
A little tip: Quiet longer let a few weeks there, even if the display annoying. As much reserve is there. Thus, considering the price at least relativize something ...