I've been a dedicated TBS WWII nut, since my early teens, and I would have to say this game delivers.
My only complaints thus far, and I realize this is probably because of limitations of the DS and it's screen size, it seems you cannot place more than one unit in one hex, other than aircraft over a hex. The game comes off more simple and arcade-like than something as in depth as the Campaign Series, but again if it was made too complex and in-depth like the CS, it would not be as enjoyable, and portable and it would find only hardcore fans of TBS (which I'm guessing few own the DS).
All in all a great and addictive game, and the single reason I decided to pick up the DS.