Saying it's still within 5% and of course explaining that premiums occur during certain markets is by definition not a pegged asset. The concept is incredibly simple.
A pegged asset by definition has 3rd party risk. A peg has to be enforce by something. Bitshares uses the free market to maintain the value. The others rely on some central authority to maintain. So you have to decide what do you trust more, the free market or group of individuals to fair and honest?