Really not much of a difference. I personally love shadows, so I would say the first one. The only thing I would wonder is about the stark brightness of the reflection on his armour, which is not followed up by a similar shadow of the tree along the ground. Also his gaze appears he is off in a daydream, perhaps moving his eyes could create more of a "story" as to what is going on. Maybe also a mist in front of his mouth showing his breath in this coldness would add a touch of realizm as well.