Brotherhood continues the story of Ezio and adds competitive multiplayer; you'll enjoy both of these features.
Presentation: Continuing the story and pulling you up from the cliffhanger that was the ending of ACII, you learn more and more about Desmond and Ezio and then are left with hanging on a cliff once again.
Gameplay: Like Assassin's Creed II but now you can use L2 to send assassins you recruited on your foes or an arrow storm to take out a cluster of enemies. Other than that, there's no difference from before, and that's not a bad thing.
Graphics: It's visually appealing but there's the rare and noticeable tearing and framerate dips.
Sound: Voice acting remains the best part of this soundtrack but the music is interesting. Effects -- footsteps, gunshots, crossbow shots, etc. -- all sound great.
Lasting Appeal: An interesting and unique competitive multiplayer component that has less people playing now that Revelations is available but it was great while it lasted. Now to milk this game for a long play period, there's collectibles and trophies to nab.