In the event of a real emergency autorotation and given the choice between grass and hard surface with all other factors equal, I'm going for the more predictable hard surface every time.
That assumes there is a road available, it is orientated into wind (or pretty close) and isn't full of traffic and doesn't have wires or other hazards. If you have to try and land across a road you severely limit your run on space and margin for error in your auto.
Imagine pulling off an awesome EOL only to be rear-ended by an 18-wheeler!