Firstly when people say this is like GTA IV you should know this is a far better game as i found GTA IV to be relatively boring and the realism to hold the game back. However with this game i find the realism is extremely fun and very accurate without loosing the fun. For example the shooting engine in this game is unlike any i have used before and is extremely realistic. It is also very realistic as there is a huge verity of things to do ranging from hunting a massive range of animals to playing "horse shoes". I love the weapons you can use in this game.
The story line is also strong however there are no real points at which you can make choices of what to do and the morality system has no impact on anything except how people greet you in the game. This however is understandable due to the massive map and massive choice of things to do.
The multiplayer is fun however i would not say it is nearly as fun as MW2. This is simply because there is less to do in it and is pretty slow moving. This said if you have some friends to play with it is very fun to go wondering around the wild west and encountering gang hide outs as you have access to the entire map which i thought was a very cool feature.
The ending was not brilliant and felt like a bit of an anti climax but the concept was cool and i still found it satisfying. (maybe it just wasn't hollywood enough for me).
Overall i would say that the game was everything i expected it to be and more. The shooting engine was revolutionary and the concept was brilliant. The reason for my 4 star rating was simply because i began to find it a bit boring after completing it and i think i will go back to MW2 as i just find that more exciting.
Basic summary is that if your looking for a beautiful western game with a good story line, plenty of things to do and you have a lot of time then this game is for you however if you are like me and you just like to pick up a game and get strait into the excitement then play it for 10 minuets and put the controller down to do something ells then i would recommend waiting for the game to go down in price before buying it.