I have to second all of this. Now I use buttermilk sometimes, just depends on if I've got pickle juice, but the pickle juice does give it a great flavor and tenderizes nicely. And, you're absolutely correct, chicken hearts are underrated. They're pretty simple to prepare and they have great flavor. I far prefer them to chicken livers. I can do beef liver, but I'm not a chicken liver fan.Tri-tip is sort of an upcoming hipster cut. It's an oddball assortment. It's basically a cut below the sirloin that has been underutilized. It's a little tricky to work with because while you cut it against the grain as with most cuts like this, the grain actually varies through the cut.
Makes good stroganoff.
For frying chicken, I actually prefer pickle juice to buttermilk lately. Whole milk and a splash or two of pickle juice. I just can't justify having buttermilk around since literally the only thing I ever do with it is frying. So I'd buy buttermilk, use a couple splashes and the rest spoils.
Also chicken hearts are underrated.