Never had a problem with grass stopping the skids from spreading on an EOL.
Since we have often discussed this very subject, nobody has a definitive answer. I can see Shawn's point, that it is harder on the airframe. And since he was an engineer with degree and everything, I tend to take his opinion seriously. On the other hand, just from the feeling of things, an auto on a hard surface with all the shudder and screeching, just makes it uncomfortable. In the end, I take what get.
Oh and crab, believe me, by far most of my autorotations in training were throttle chops without warning. Whenever there was a dull moment, one could be sure it got exciting again any second. Everywhere, at any time of the day. The autorotations during nighttime to an unlit runway were particularly exciting. I had to stare down along the beam of the landing light until I saw the runway, that was the moment to flare. My instructor never let me turn the runway lights on. Never. Just once I wanted to see the ground light up, but no. Everything always to the unlit runway. Chased foxes around the runway though.