Would you say one of these is better than the other? Apart from one falling off the hub when the wheel is removed obviously. I'm thinking from a safety point of view more than anything. They aren't Merc specific, I couldn't find any jpeg images on fleabay but you get the idea I hope.
The top ones which are known as 'hubcentric'. The protuding lip at the centre hole is a centre register which like the one on the hub locates the wheel concentrically (the wheel bolts are there to clamp the wheel to the hub, not locate it). Unsurprisingly the diameter of the centre register varies with manufacturers, it's 66.5mm for Mercedes IIRC.