I was very disappointed in my chanter because of this "slowness". Though the power of the class immediately shows through the passive buffs and the phantom, it was really boring seeing my main character do so few interesting things.; while other classes were doing some amazing things already.
Since getting about 30 hours into the game though (playing on hard), that has changed though. Now that fights take a lot longer and I've given her other things to do, like casting scrolls, she starts to shine more in her role.
The paralyze / charm aoe effects can be serious gamechangers when a fight goes the wrong way initially and they continue to be incredibly awesome lwhen a fight drags on (though I need to remember not to paralyze my allies too).
Those abilities show the strength of the class.
On the other hand, the direct damage abilities are incredibly weak and definitely require a buff. They simply can't compete with even level 1 druid / wizard spells despite the long spin-up time.
Perhaps it would also be interesting to add some active effects to alter your songs. Like speeding up / slowing down your songs for more phrases or stronger buffs respectively (decrescendo, crescendo perhaps?)