Shorthaul earlies makes me tired, really tired, 5 earlies in a row take its toll. However, one good night of sleep, and I am fully recovered. But this is only 50% of flying, there are also the other 50%, the late shifts where you only start in the afternoon and end usually between 22 and 23 o'clock. That is really chilly.
My colleagues on longhaul tell me they have more colds, their immun system seems generally lower in their experience, and over the years most (funnily not all of them) developed some sleep disturbances. And they fly 900h block max, no factoring like at EK. So I guess EK longhaul is even harder.