As luck would have it, the very first trip where I took the maxtrax they were used. I wasn't even towing the camper but managed to get stuck on a difficult beach exit (heading over the dune towards the beach). Max-trax didn't get me out immediately but after rocking the car a bit and sticking them further under the problem rear wheel they helped me drive out. Useful but I probably could've used some branches or something.
So, 10 years driving on the beaches around SEQ without an issue and first trip that I take the maxtrax I need to use them! :-)