I've recently mistaken some of my Agfachrome slides for Kodachrome-- their color has held up very well. My E-4 Fujichrome has been fading- mainly yellow, making the famous Fuji greens look muddy. I only bought E-4 films when I was too broke to afford Kodachrome, (around half the cost, with processing) and for that used Agfachrome after I 'discovered' it. The only thing I didn't like was its graininess, but back then nothing compared to Kodachrome in that regard, especially K25.
I'l try the Ferrania if it comes out. I don't know how the last E-6 films were from them as I never tried them.