Full contact karate practioner beaten badly in prison by a fellow inmate:http://www.kyokushin4life.com/forums/showthread.php?t=9902
Of course doing full contact karate doesn't make someone Superman. The Royce Gracie fight also shows how badly a full contact karate fighter can be caught out by a grappler too.
I certainly would not describe full contact practioners as "Neanderthals". I would question why they spar they way they spar and how much sense is applied to it vs how much is machoism. I would also question the belief this makes them better than other karate-ka. I may be wrong, but didn't the founder of Ashihara Karate leave Oyama because in part he felt that Kyokushin Karate with rock 'em sock'em style favoured larger, more powerful fighters? Didn't he at least try and introduce more evasion in Kumite?
The question I would also ask is why do you care what other people think? If people are ignorant about what you are doing, that's their problem. I've never considered using martial arts as an affectation to impress people. Just do your own thing and don't worry about what other people think. Whatever pastime you do, there will always be a queue of people who don't understand it. Just spend time with people who enjoy what you enjoy and get what it's all about.
I'm playing devils advocate here I know! Just to keep some discussion going on FA forums. It's a good topic.