Personally I always perfer to park the car myself, spent the extra 5 minutes in the bus transfer and know that no-one will be driving my car.
Last time we went skiiing a friend who was fling in from SA to flow out to meet us a day late put his car into valet parking. After a delayed flight, missing his connection to france then needing to drive to drive to another airport to get another link flight he went to pick up his car and was told
"Oh I'm sorry sir there has been a little accident. We have scraped the side of the car along a wall.....Don't worry its our fault" To say he was about to go ballistic on them is an understatement with all he had put up with that day.