Yes. He is a sex addict. At the momento, he has more than 30 illegitimate sons and daughters. The oldest of them is in her fifties right now and lives in Switzerland, where she's being taken care of at the taxpayer expense. She's mentally challenged, as are some others, Infanta Elena for example. As a Bourbon, what can you expect after centuries of inbreeding?
He's also bloodthirsty. He loves hunting and bullfighting. Tell it to Alfonso de Borbon y Borbon, or Sandra Mozarowsky.
The former King of Spain might be close to kick the bucket. Workers from Zarzuela palace report that he's not able to walk anymore without help. That he holds onto furniture to move through the palace. He gets lost in his own house.
http://www.zoomnews.es/sites/default/files/images/201309/don_juan_carlos_rey_getty_230913.jpg
He looks like theres nothing there anymore.
A month ago, his abscence on the 40th anniversary of the first democratic elections after Franco's regime wasn't unnoticed, could that be because of health problems?. He loses his temper too frequently and he doesnt even care anymore if he's in public. He had a fit of rage because his driver "didn't even know how to park properly". Some weeks ago he shouted to an associate of his in the middle of a restaurant because journalists appeared and he considered it was his fault. He talks nonsense too often lately.
Anyway, keeping in mind that he's always been a drunkard that never worked in his life and his genes are defective, I'd say it'd be a miracle if he makes it to 2018. If he manages to achieve it, he'd be a good candidate for next year's list. Just sayin.
About Don Juan Carlos vs Prince Phillip, I'd say the former has way more chances of... winning? Despite being younger (He'll be 80 in january).