ahh theres the trick, after you play a song when it goes back to menu it has a replay of your previous performance. but for somereason that always has some terrible lag in it.. at least for most players. the actual playing will have no lag.. but the replay will be out of sync

also that article on how it fails at teaching.. the part about the dynamic difficulty .. his complaint was that he wanted to play songs he already knows at full difficulty right off without going thru the easy stages.. how is that failing at teaching? more like failing at not teaching and letting you play what you already know. also it does not penalize you for playing extra notes, so if you know the full song,, you can play the full song even when on easy