You no longer need to worry about text limits on posts, as Facebook now allows up to 5,000 characters. You are now free to write complete thoughts and break up your status updates into paragraphs to make your posts more readable. You can be one of those Internet novelists and serialise your Magnum Opus in the manner of Charles Dickens.
However, longer posts will consume more space in your followers' News Feeds. They may find it more than annoying if you take up too much screen real estate, so use this feature sparingly.
It's worth noting that after a certain length, posts get truncated on-screen anyway, so it's less of an issue on a Wall or Fanpage, but you don't want to look like a spammer, or worse - a bore. Write what you need and no more. RC