i wouldn't call it a great game yet.... if they fix some of the UI issues (slow menus, crappy song selection screen, constant forced tuning) it could be a very good game. i've yet to have a session of this game where i didn't get frustrated with one of these issues at some point.
if they improve the charts to make them more readable, or better yet, offer a tab option, then it really could be a great game. as it is, it's awesome technology with some good ideas, poorly implemented interface but lots of potential.
here's hoping for Rocksmith 2.