DickTrickle
Definitely NOT Furor Planedefiler
Bards are the best 6th group slot character, that is 0 question. They also have one of, if not the highest, skill cap.
That said, 1 bard in a raid is having magnitudes less impact than having 1 enchanter in a raid. And I don't want to hear about raid-wide mana song, because that shit ain't pumping during boss fights.
If you're looking to challenge yourself, bard is definitely a good choice. But at the higher end so is enchanter.
Conversely, it's generally way more useful to have 3+ bards than 3+ chanters (except for specialty situations like Rathe or where good charm pets are easily used).
Though, I'm curious as to why mana song wouldn't be playing during boss fights? Every guild I've played in made sure it was playing during boss fights. The only time we didn't was during a pull.