I haven't played 5 yet, but I do have 3 and World Tour, and if I only judge it on gameplay, 3 beats WT hands down. The hammer-ons and pull-offs are pickier than Nazis in World Tour, and if anything scratches the tap strum bar, you're fucked, because the game will think you're tap strumming all the time and you instantly fail every song.
If I judge it by the setlist, 3 is, again, much better than World Tour.
If I judge it by the setlist, 3 is, again, much better than World Tour.