For some uses (salsa, tacos, etc) they seem too mild to me, but I'm into hot peppers and unique pepper tastes so that's a subjective assessment. I use them anywhere I'd otherwise use a bell pepper but where I want less watery flesh... meatloaf, on pizza, in salad, chili, or just eat it fresh cut into strips. Deep fried, some cream cheese on it, in soup, or if they're large enough they can be stuffed h'orderves.
With mine it sometimes depends on who might eat them, I've had larger variabilities in the heat level of this pepper type than most others, ranging from barely hot to about the same as an average (full strength, not americanized/mild type) jalapeno, with no telltale signs how hot it will be till you taste it (though if you see a fair amount of oil all over the placenta around the seeds you're fairly sure it's not going to be especially mild).
Paprika, they aren't so suitable for because their flavor density is lower than most other hot peppers and besides the heat the overall flavor is more neutral, though that increases a little if you leave them to ripen to an orange or redder hue. You could do it, but I don't feel it'd be interchangeable with what people normally call paprika. There is a different type of hungarian pepper more often used for paprika, it has more of a spicy taste in addition to sweet and mild heat and ripens far further into a deeper shade of red than a hungarian yellow wax does.