I hope the HUD won't be intrusive. I was happy when I saw "HUD-free first person-view" in the article.
I hate HUD

Give me some visual and audio stuff instead. Heartbeats, panting sounds, blur, etc. I like that much more. You still get to know your health and everything, but in a neater way (I think).
Concerning compass, I'm not sure. I like getting lost, it's a wonderful feeling. But I understand some other people don't like that.
I'd prefer no compass to be included I think...
Landmarks instead