I really WANT to like the app but it's just too limited and a little buggy. Recently, my wife and I both had problems with the app not showing our friends lists (me - iPad 2; her - iPhone 4s). Also, yesterday, the app kept crashing while I was simply attempting to comment on a post.
If I just want to read through my news feed, I go with the app. If I want to post, comment, tag, or do anything else, I usually have to go through Safari.