HDC is the only 'real' difference between Cross and normal 4x4. The Drive Control in Cross has 3 positions - Normal, Off-Road and HDC. Normal is the same as default in the 4x4, Cross Off-Road is the same as 4x4 with ELD selected (preps the early locking of the diff and pseudo cross-axle braking) and then you have HDC, which would be the same as power downhill braking, if the driver of a normal 4x4 could do it!!
Lifted ride-height is through the 185 tyres, as opposed to the stock 175's we get on the 4x4, but other than that they're the same.
Lifted air-intake is the same as the stock 4x4.
Apart from the looks, which I agree look excellent on the Cross and the front approach angle will be slightly better on the Cross too. Not much in it however, but useful none the less.
Just get those tyres sorted! How ironic that 4x4's in the UK come with full Winter spec tyres, yet you're being told that the stock 4x4 in snowy Norway comes on summers..... Gotta love Fiat!
Yup, that's what I understand the differences to be....