As for Heidegger, I find his ideas highly useful. They provide a means of understanding how people are blinded against viewing alternative models of reality, thus stymying constructive discourse. His work is also a reminder that it's easy to fall into the trap of being captured by a projection ourselves.

Ironically, his affiliation with the Nazi party was itself an example of this. If he'd applied his own critiques in the Question Concerning Technology to the Nazi government, I think he may have had a change of heart.