Not the best RTS out there today.. but you could do a lot worse.
More units and more expansion into the air could have made this game greater... but its still quite solid and the campaign will keep you going for awhile. Multi player has always been the best aspect of this series, and while it didn't bring anything much new to game play and overall strategy.
Been there, done that but its still a great game and worth buying if you have money and are bored with your current RTS. I recommend it to those who have played the other games in this series, while it doesn't do anything new, the aircraft, new units and factions (plus new single player) add to the experience of DOW.