I have only 1 more segment of The Truth to get, and I already unlocked Altair's armor. I have to say, they've done a good job with filling in more spots from the first one. Desmond does have a bigger role, but there is also much more uncovered. They're setting it up perfectly for another sequel, and I almost can't wait.
I must admit that I bought the strategy guide the other day, but barring 1 of the truth segments, I haven't needed to use it yet. I'm kinda proud that I figured out almost all of the truth puzzles on my own. A couple of friends helped me with others, and I used the guide for one. Everything else I have been able to do on my own. I think what I will use the guide most for is finding all the feathers since they're spread out all over the place. I've found 1/3 of them just by running around and doing the story.