I've done 2000km in mine and not noticed the level drop at all. But then my Stilo Abarth does seem to be special (touching wood)...
FIAT quote a ridiculously high consumption that will cover all cases.
Actual use might depend on how the car was first run-in, i.e. how vigorously it was driven. If it was driven too gently, the rings may not have sealed very well before the bores glazed. If you drive it properly and use the right grade of oil, it might come right (in my experience of previous cars).
I have heard of a trick that involves pouring ATF into the engine; apparently it helps to un-stick and re-bed the rings... I think that there are various additives you could try that would work in a similar way (probably safer for the catalytic converter too).
I don't think the standard specified oil is 10w60? - see attached pic, 10w40 or 5w30 for really, really cold climates - but thicker oil will reduce oil consumption in most engines. All engines burn oil to some extent, but in my older FIATs (e.g. 128, Uno 60) it was always a tiny amount (i.e. less than 0.5L in 10,000km). Yet the handbooks have always quoted more like 1L/2000km.
-Alex