I have only (well, Youtube as well but no teacher or anything) used Rocksmith as my teaching tool since I got it and a guitar last November and I would say yes.
I have come a long way since I first plugged this in to my PC for the first time.
Here's a video of Hypnotize, only played it 2 times before this run so that should tell you something on how far a beginner can come with just Rocksmith. I never would've played anywhere near as good so fast just 6 months ago or something. http://www.youtube.com/watch?v=PDq9P1rSHpU
How often did you play and train until you where up to this level? Daily i presume. Btw thats some pretty great playing, really awesome.