Just to add my two cents.
Played the first 2 hours up until right before the train. Took my time and turned off the HUD. Man, is it pulling me in with the atmosphere.
I usually tend to rush through SP games because I stick to the main story and everything else is usually added as just gaming filler. But this.......... I am allowing myself to actually soak in a game rather than rush back to my usual MP FPS games (I tend to enjoy the social aspect of multiplayer) and I enjoy that the beginning is paced methodically. To me it mimics exactly what so many western movies are.
Why I think people say the beginning is slow is because the game is deliberate in what it wants to do. The beginning is finely crafted to ease you into systems while engrossing you in what the actual West was like. People may not want that from the game, but I think it is a breath of fresh air. Too many games these days play off the ever increasing nature of people to need stimulation. I find that this game is, so far, the antithesis of that. It revels in the untamed West and I applaud them for being brave enough to do it in a world of increasing stimulation.
Some people don't like it. That is fine. But personally I am enjoying the contrast between this and all the other high octane games that come out left and right. It's like I get to experience the western movie and life. I'm a lawyer in California so this is the closest I will ever get haha.
The controls could be tightened a bit more though. Not a huge issue for me but I'll be messing with some settings when I get back to it.