They have high no-show (biz changes) factor, also pax upgrade w/miles. There area fair # of misconnects, too. Those flights go like clockwork when possible. NRT is very efficient. It's a crapshoot. DL will upgrade if coach is oversold based on fare, status, etc. NRT flts are the only ones I've seen w/such a disparity AVAIL and Auth to sell in biz elite.