Yeah, it is still definitely lacking features, but I think it is pretty usable right now. I've been using it instead of Rocksmith for a while.
Btw, note detection is (to some degree) already implemented. If you if you have your guitar audio input from your DAW enabled for the track ChartPlayer is on, it will try to detect notes/chords. You'll see them light up when detected. You can make it easier to see by pausing the song (hit the space bar) when a note or chord is active and try playing that note/chord. Right now I'm not keeping track of how well you are playing. I may add some sort of tracking feature, but I'm not planning on "gamefying" it too much.
I'm definitely planning on practice features like looping a section (pretty easy) and slowing the speed down (harder).