Of my experiences with classes so far, since I've gotten the chance to fiddle with a character a friend of mine owns that currently has all of the DoW classes at 50, I can more accurately describe my impressions of each class.

Dragoons
This class is highly mobile and can easily jump in and out of a fray with enemies. Their forte consists of very powerful strikes at the expense of some of the longest cooldowns in the game. For this reason, timing is everything, and making sure you're properly buffed before unloading on a boss is paramount.

Monks
Of all the dps classes this is the most technical while also offering the highest "potential" dps. Of course, due to the stress of positioning and keeping up Greased Lightning, this class easily drops behind due to actions from bosses and special mobs. Positioning is paramount for this class, and even one mess up can weaken the next full rotation of Monk dps.