Reliable?
Sort of. As ML mentioned it doesn't take too many objects well, but other than that it's *generally* good.
There are the occasional "glitch games" where the players are desynced, which isn't easily detected. Or where positions are different for at least one of the players.
Easy to use?
If you can play the game, you can handle it in-game. Getting the game set up is not much of a problem (esp using hyperlobby or similar) unless there are router problems etc in the way. Meaning it's usually the first time that gives trouble.
Improvable? See the suggestion box thread
One consideration for DW wargaming is the scope of the conflict. Truth to be told, DW doesn't handle the larger scale engagements well, especially when carriers are included. (Leaving a huge burden on the mission designers to get it right)
Strategic AI is nonexistent - there is only what the mission creator specifies, and what each platform does on its own.
If it's to be an entire war, then there would have to be somebody (human) in an umpire position, to take the "orders" from the highest-level commanders of each side, and create the missions based on what forces would be meeting each other.