I was gifted a Fender a few years back and have a small amp but never got beyond self taught basic chords and walking a few scales from a DVD trainer. I should have got lessons to learn more but other hobbies took precedence.
This guitar, while not a full proper guitar, is still a great way to have fun and learn guitar basics at the same time. The lessons are good, if a little thin, but the best thing by far is picking a song you like and learning how to play it. The fingering is the same, bar the callouses, and the game is a little forgiving, much like my Fender with high distortion ;)
I'm not good enough to pick it up and sight read songs like I can with the game controller guitar so in Pro mode I do have to invest a lot more time to play a song through, but it is very satisfying. You can use the Mustang in simple mode and then the top 5 frets are your controller buttons but they are spaced like a real guitar so it's not as easy as using the 5 button controller. You're probably better off with the controller for just jumping in.
I have 5 other rock band/gh guitar controllers and the build quality of this is by far the best. The parts clicked together well and it is rock solid. A good looking guitar as well. Makes the others look like the toys they are (not that this isn't a toy, but it's damn close to a real guitar). The nylon strings strum accurately and are silent. One thing to note, no whammy bar, but I don't find that a biggie. There are also only 17 frets but that has had little impact so far either (and I guess will have none unless you want to use this as a full midi guitar and shred lower frets).
I also prefer having proper xbox buttons and d-pad on this guitar rather than some of the weirder configurations on other guitars.
I'll almost certainly get the Squier when it is out as well, but in the meantime this is a superb instrument and with any luck I'll be half decent by the time the stringed version is out.