Surprisingly I would recommend this game rather to somebody who does not own Halo 3 rather than current players
Why should I pay full price for what should be DLC?
Campaign is not that bad; Firefight is a good feature; You can still use your Halo 3 file share, maps, and play with other Halo 3 players with your second disc.
Why is it best I avoid this product?
Short campaign; Firefight, while good, not addictive; Same Halo 3 multiplayer, same recycled elements besides firefight online which is only up to 4 players.
This game is not bad, just not worth the $60 dollar flash. Halo 3 is currently somewhere as $30 and a big portion of it is online so that takes $15 dollars off and adds to ODST, with the addition of Firefight which adds $5 dollars, and the 5 hour campaign adds $10, so over all this should be $30 itself. But Halo 3 started as $60 dollars but the case is that Halo 3's value is now around $30 and so should ODST's value. This is not bad, just not a full value product. If you did not like Halo 3, you will not like ODST.