I have noticed that blooms of my cymbidiums in Semi-Hydro last much longer than the blooms on a cymbidium that I got as a gift that was planted in traditional medium.
The cymbidium in the traditional medium bloomed about two weeks after the cymbidiums in Semi-hydro, and now the blloms are starting to fade, while the blooms in Semi-Hydro haven't lost any of their beauty.