I have Rocksmith 2014. It's fun to play, fairly accurate, and for me, it's more or less useful for learning good songs that I haven't played before. It's super handy for slowing down tough parts of songs to learn them. Ex: You can turn YYZ's main riff down to 50% speed and have it slowly speed up as you start hitting all the notes in it. Very cool. One thing I noticed improvement in from playing the game: jumping to high frets without looking. There's no time to glance down at your fretboard for more than a fraction of a second without getting lost, so you get pretty good at keeping your eyes off the fretboard.
Does not teach any theory whatsoever but at least it names the chords when you play them.
Also it's pretty crappy at knowing when you're doing a 'special' note like a slap, pop, palm mute, hammer, etc. If you get the basic frequency of the note down, it accepts it. So even though it's telling you to slap the note, you could just finger it and it would say 'great job!'.
The session mode is really cool. Nice way to jam by yourself and it seems to be a lot better than most of those crappy drum loop pedals/programs you find online. The band kicks up the tempo and feel when you do, it tells you when you're playing out of key, etc. Handy for learning scales/theory in that regard.
There's a lot of other instructional stuff that I haven't played with yet like the videos which *do* focus on proper technique but really don't grade you on your own performance of them.
One kind of cool thing for the FX junkies out there: When you finish a song, it unlocks the patch for you to modify. Pretty snazzy for trying to steal a tone from a song.
I'm sure tons of people are basing their opinions of this 'toy' based on assumptions rather than actually trying it, but I guess that's just the way it goes. You'll always get uneducated/inexperienced opinions on products sprinkled in with actual knowledgeable reviews. So what if it's not teaching every single aspect of music to someone? You gotta start somewhere. Does Bradley Nowell deserve less credit for Sublime because he didn't have professional instruction? Does Matthew Bellamy deserve more because he's classically trained? If the game creates more interest for music, praise it. Look what Tony Hawk's skateboard game did for the skate community... skating was pretty much dead when that nowhere-near-realistic game came out and it made a major impact on that industry. If this game did the same for music, would you still trash it because it wasn't the same as a per-hour instructor?
Also... is that friggin Andy from ProGuitarShop.com doing the voiceover??? I swear it's him.
In the end, RS is cool for getting gamers to try something other than a controller, and fun for people who can already play. Not to mention that not everyone has instant access to a bass/theory teacher. Try growing up in a rural area and picking up a hobby that nobody else does for miles. This game would be a great way for those demos to pick up music. Not the amazing learning tool they market it to be, but it certainly doesn't hurt.
Recommendations for future versions: Slowly ween the player off of tab-like notation and on to sheet music as their technical skills improve. Drop out the actual note-for-note fills and force the player to do their own fill in key. Ear training. Metronome based rhythm training. The technical bits are for the most part there (low latency, cool amps/effects that sound pretty good, etc.) for this type of educational content, but I guess they found it to be not gamey enough to include. I'd really like to see them take this game to the 'advanced' level and use their technical abilities to create an array of instructional content built around the game engine they already created.