There are tons of people for the J1 attack. However we have played our last 6 games with Japan attacking on the 4th round. Even though the UK gets extra money from the islands it doesn’t compare to the USA’s bonus money. last 6 games Japan has taken India in round 5 every time.
Now we have played multiple games with the J1 attack and are about 50/50 on who wins.
Its worth getting cause when AAE40 comes out you will want both to play the combined game. Also the introduction of new rules and units (convoys, declaration of war, air base, naval base, tactical bomber, mechanized infantry) make the game far more enjoyable and adds more depth and breadth to the series, further setting it apart from other board games.