I have it. It's big and beautiful. There is a brilliant operational game underneath, too, that's hard to find. I just wish life gave me the time to fully explore it.
There are three levels of the game: engagement scenarios (thinking of the attack on Pearl Harbor or Wake Island), which are essentially die-rolling tutorials with almost no meaningful decisions. But they teach you the mechanics.
Then there are Battle Scenarios, such as Coral Sea pr Leyte Gulf. As the forces are pre-designated, you get to maneuver them around the map (usually as they were in history), chuck a few dice, and that's it.
Then there are the Campaign Scenarios (and the Strategic Scenarios), which is where the operational challenges are in this game. They are months-long affairs that involve activating some of your forces (using operations points) and conducting a sustained campaign, such as the seizure and sustainment of Guadalcanal. You can't just move all of your forces--you have to activate a subset of them, and the length of time they are activated depends on the operations points you spend.
Like any Mark Hermann game, there are a lot of subtle design choices that you may not -- and I certainly don't -- appreciate until you see them in action. The telescoping time element is also tough to understand until you see it in action.
If you do pick it up, and ever want to play some on VASSAL, I'd love to find the time to play some more.