Granted Java has more IPC value, but DNG I believe is far superior from an annoying factor for Japan. The list of SZ and territories that can be hit from DNG with a NB on it is pretty insane, and I mean insane.
Iwo Jima, Okinawa, the ENTIRE Asian coast with the exception of Korea and the Russian territories. Every DEI, Calcutta, Caroline Islands just to name… well most of the Pacific Board.
The great thing about DNG is that DNG is a VERY annoying place for Japan to get to. About the equivalent of the US trying to get into the Med in the Atlantic in regards to what it has to do just in planning to get there.
Toss AA guns from Anzac on there for the first few turns and Japan will have a VERY hard time taking it away from you.