We've been parked on all 3 types of surfaces. Not full timing, but sometimes for a week at a time. I'll take concrete any day over anything else. Anything other than concrete or asphalt, and there is always the chance that the tires will sink into the ground, sand will shift from under the stabilizer jacks and even sand can shift under the tires. I always used lumber under the tires when on anything but concrete or asphalt. Even then, at least once a day, the stabilizer jacks need to be tightened up. It's no problem parking on any of the three surfaces, it's just a matter of paying attention to things after you get parked. But, that's the beauty of traveling ... no two campsites are EVER the same.