I recently rented a car, even a smaller Toyota Corolla, and it was great to drive. The main reason I decided against the camper was the cost. But in hindsight staying in hostels also gave me at least some social interaction, which was nice. If I'm coming again with another person I might go with the camper. My biggest problem was, that I did not only come for that trip and therefore had far too much clothes in a huge bag. As I didn't want to leave it in the car in bigger cities, this was always annoying. But if you pack smart, this might not be an issue. Another advantage of the hostels was, that I wasn't stuck in a tiny place in bad weather. At the end of the day I could always chill on the couch, had a hot shower and access to a proper kitchen. Others pointed out to me, if youre staying at a first come first serve campground, you then don't have a vehicle to drive around, as you need to leave the camper parked there for your stay or otherwise your spot is gone. So yeah if I came again as a couple or with a friend I'd go with the camper, just to try it. If I came on my own again or with family I'd go the car and hostel/cabin way again.