First off, I just got 100% and I must say that I love this game. I truly haven't wanted to play a game this much day after day since Uncharted 2 or Kingdom Hearts 2.
The game is beautiful. From the snowy mountains in Tall Trees to the to hot and dry deserts of Mexico, this game is just a sight for sore eyes. And its a sandbox. A SANDBOX! Don't even get me started on the horses. I had my friend come in to look at the horses in the game. (She's takes care of them on the weekends). Even she was blown away on how realistic they looked. The night sky is also a thing to behold. But my favorite times of day are dawn and dusk. Seeing the sunrise or the sunset makes me feel so warm inside. (I mean that in the most manly way possible.)
The story, in my most honest opinion, was fantastic. And i'm so glad that it lasted so long. I honestly thought that the game was going to when John was about to take Fort Mercer with everyone. I hear alot of people say things slow down in Mexico. I enjoyed it the "revolution" feel it gave. Another thing people complained about was the conversations the characters had during the trips that they would take on the story missions. I personally felt that they added to the feeling of the old west.
One thing that I noticed about this is game that...the side mission never get boring! At least for me. Hunting, gathering flowers, sharp shooting, stranger missions anything! It was a lot of fun. The stranger missions I found very interesting.
I just found the whole thing extremely immersive. It was so much fun.
Now i have to play the mulitplayer ;)