Yeah pop in was rather noticeable, especially on larger areas with a lot of trees. However the odd thing is, I'm not bothered by pop in like that as I am with tearing or huge amounts of jaggies.
Funny enough I am your direct opposite. Tearing and aliasing don't seem to bother me but the first thing I notice in a game is pop-in. Not that it distracts or diminishes the experience but I tend to notice it more than the other stuffs.