I'm a fairly accomplished guitarist, and was given both an old and new Rocksmith as a joke. I found them to be quite counter intuitive, mainly because the focus (at least for me) was on trying to follow everything on the screen, and not paying attention to what I was actually doing. For a song I never played before, I found I hadn't actually learnt the song by the end, but could play it by reading the screen only. There is also the issue of not being taught how to improvise and how to actually create anything. Perhaps this is the view of someone who shouldn't be using it though (which I don't other than that first day). The tips for technique are great though. They are thorough and well shown in the new one. However you could just watch the whole thing on youtube if you wanted.
It's probably a nice way to start, but I wouldn't rely on Rocksmith alone.
I think there is a lot to be gained by mixing and matching these things though. Just make sure to try looking up a slow simple song via a tab, and learn to play it. Start super slow with a metronome and keep building up. Then try more difficult songs as you go. Learn some scales, check some youtube vids when you get stuck or confused. Mess around as well, you'd be astonished what you can do.