Hacker News Reader

It hangs all the time for me, video scrubbing halts the entire tab, and it uses a lot of CPU sometimes.

That's not expected. If you can send me a performance profile I'll look into it. My nick @fb.com.

Any chance you're using Safari?

It loads very fast for me with Safari, but I regularly get an empty newsfeed or only 1 or 2 posts.