[WolfeMacleod]

I have both the first Rockmsith and the new one, 2014.
The first one was a little clunky, but pretty good overall. WORLDS ahead of Rock Band, even with the "pro" guitar controller that Fender put out.

The new 2014 edition is much better than the first one, even. The "Session Mode" alone, Id say, is a very nicely added feature. It allows to create an A.I band, pick the key, grooe, etc, and jam with it, showing you the scales along the way. I'm digging that quite a bit.
There's quite an extensive chord library and chord-skill building games. Chords have always been my weakest point.

One point about the Audio -- do NOT use HDMI for the audio... route it directly to a stereo input, no processing, and you'll get less lag than if you use your TV audio.

Overall, it is very good. Well worth the price of admission. I would pick it up, get the kids playing it, and see how they do. If they take to it, THEN put them in lessons with a teacher... or not at all, if they progress quickly.