1) MNK - My least favorite class. Absolutely terrible for solo play, requires a long warm-up to get to max power, and 99% of the time greased lightning falls off in between each mob (and poorly timed boss jumps). Extremely terrible AoE skills as well. Howling Fist should have a shorter cooldown xD They also have almost 0 utility outside of the occasional mantra, meh.
BRD - Extremely versatile, they have a lot of off-GCD abilities to weave into their rotation that means you're almost constantly occupied. Have the highest single burst DPS in the game (if I'm not mistaken) if you pop all their cooldowns at once, you can do that every ~2min I think. They're my third fave class after SMN/SCH combo.
3) SMN is the 2nd highest DPS in the game, only MNK can compete and they require ideal conditions (sustained single-target).
4) BRD is really desired in end-game, even if you're only average, however if you are an excellent monk people will fawn/fight over you (because unbeatable DPS).