I'm sure this question has been answered a billion times and I'm sorry for it, but is this game a decent tool to learn guitar? I took lessons ages ago, but I don't really have the patience or attention span (I have some rather severe ADD, and yes I was officially diagnosed by a psychiatrist) to do something for its own sake. I basically got a few chords, hit a wall, got discouraged, and how have a fairly nice guitar that's been figuratively gathering dust in its case for the better part of 10 years.
However, I do respond well to "game-like" learning and stat tracking software and resources; would Rocksmith be a good resource for me to get to the point where I'd be good enough to practice without it? I obviously don't expect to be an amazing guitar player with it, especially as I'd be starting at 24, but does the game have a robust enough training mode to be able to learn guitar from 0, or is it a little too hardcore for that?
From my personal experience, this game can make you a decent guitar player if you just keep playing. The main problem is that it could also make you pick up some bad habits that a guitar teacher would probably help you avoid.
I picked up my first guitar with the first game in November 2012, only had some minor experience with acoustic before that. I now have 429 hours in RS1 and 469 hours in RS2014, most of that is actively playing as well. Rocksmith has been my main way of learning how to play, but I have also watched lessons on youtube and just played along with normal tabs online.
Just to give you some sense of what progress I have made, here is my first video I uploaded about 2 weeks after I got the game and guitar.
https://www.youtube.com/watch?v=LnPBGWD_x1U
And here is one of my more recent videos.
https://youtu.be/hp9U-tyXKdY?t=44
That said, I have it pretty easy to learn new stuff (especially when it comes to rhythm games) so how quickly you and others will make progress is hard to say. But if you put the time into it, take it slow and just have fun with it you will notice yourself making some nice progress pretty quick.
I still have a lot of stuff I need to work on before I would even consider me a good guitar player, but I'm slowly getting there and Rocksmith has helped me keep the interest up at all times.
The game has a lot of tools to help you improve. Minigames that focus on specific things like strumming, sliding, bending, string skipping, scales etc. It also has plenty of lessons where it goes through the basics and advanced stuff.