most people say bard sucks but honestly, they havnt tried it out yet. it has a buff skill which adds (Player level) X 0.3 strength into any hero which lasts 90 seconds. which is really good.
So if my bard is level 50, i can buff anyone for an additional 15 strength. Thats ALOT of armor penetration, 15 extra damage for strength based characters (especially good with zerkers), and a small amount of crit chance.
On the bigger picture, 15 strength is as good as 29 levels worth of stat points.
However bards are agility type T.T They should be remade into strength.