Important you need the original Fallout3 to play this add-on.
I was disappointed with the Operation Anchorage/The Pitt add-on. This however is far far better.
First Broken Steel which is actually an extension of the original game. For those who haven't played or completed FO3 I won't spoil the ending, just say that instead of the game finishing as in the original it carries on with the player continuing their adventures with the Brotherhood and the Enclave. You still get the original cut scene ending which does make the additional continuation of the story a little disjointed but this does not spoil the story or the enjoyment.
Broken Steel does fall a little into the trying to be a FPS trap that hampered Op Anchorage and the main quest can at times seem to be a mindless blast (it's fun though) but the side quest are interesting all I'll say is remember to visit places from the original game and not just the new areas that appear on the map. As it does use the original map it doesn't feel as 'on rails' as the previous add-on although there are plenty of corridors to run and fight down. They have also put in some little physics touches as well, for example, if you find a house of cards and remove the bottom one it collapses nicely.
I give Broken Steel a 4/5
Now Point Lookout which to me is a true add-on the player buys a ticket and takes a boat trip to Maryland where there are a number of quests and side quests to play and a large play area to explore. If you think of the Florida Everglades crossed with the Blair Witch Project it will give you some idea of the scenery, swampy and overgrown with some quite eerie locations. Graphically the views can be quite stunning on a powerful machine.
If you want the game to last longer don't fast travel anywhere as you will probably miss something it does not take too long to walk from one end of the play area to the other.
I did point lookout when I was nearly at the end of FO3 but unlike Broken Steel in which you have to complete the main FO3 story arc you can buy a ticket and travel there at any time.
The monsters and opposition that I met were quite tough although I'm unsure if this is because I was I high level character or it is generally harder to play the add-ons.
I give point lookout 5/5
Both these add-ons are a vast improvement on Operation Anchorage/The Pitt and considerably longer I would recommend buying this pack rather than the Op/Pitt one for certain as it will extend your enjoyment of FO3 for a fair number of playing hours (depending on whether you rush around completing everything or take your time to explore).
So overall I'd say that if you enjoyed FO3, as I did, and want more this is a 4.5*. However if you are bored with FO3 I'm not sure this will be for you as it doesn't really add anything new in the way of game play just more of the same.
Explore and enjoy.