My experience with Lance Warranty has been stellar...had an issue with the remote control which the dealer could not fix and was recommended to visit the factory. They diagnosed and fixed the problem on the spot. Had another issue with front jacks. Made a video of the problem emailed to the dealer, they ordered new jacks got them installed problem solved.
To be honest, I liked the Mammoth better but didn't want to pay $58k vs $45k for the Lance 1172...well, I would have but the boss didnt. I think, the finishes of the Mammoth are much higher end.