Re: duck necks, I just can't believe they'd be much fun to eat. Whenever I roast poultry, I always save the neck & the giblets to cook up for the cats. Picking the meat off of the neck is messy & takes some time, plus the bones fall apart easily. Not my idea of fun - but then there might be a preparation method that does more for them.
As far as other organ meats, I've never been a fan of beef or calves liver, but do enjoy veal & lamb kidneys. I also LOVE chicken livers, & a grocery in NY used to sell Italian stuffed pork livers that were fabulous.
And while my grandmother used to make a wonderful tripe soup, I've never been able to get up the gumption to even try sweetbreads or brains. Something about the appearance & the texture turns me off.