I´m hardcore samurai during I has some kind of katana fetish.
Well both job is pretty fast pace and strong melee dps.
Samurai Pro:
Strong single and AoE dps, fast pace with kenki, a 20k dps button, easy learn to boss and easy recover from death, you get coolest weapon look.

Con:
no utiliy, weak range attack, casting bar with 20k dps button+dot+AoE, waste dps kenki with dash out n in, hard to join party in PF.
Weakness: Get lock out from PF

Monk Pro:
Strong single and AoE dps, fast pace, utiliy everyone love it, easy to join party in PF.

Con:
a bit more movement then samurai, range attack nope nope, take some time to recover from death but not long!, has to learn timing with boss jumping.
Weakness: God my eyes and mind hurt from watch+countdown GL time remain.