Pros and Cons of All Classes

Blade Master

 Spoiler

Pros:
Fast and mobile.
One of the best rushers in the game.
Fun to link skills.
Two weapons, which gives an advantage in weapon attack and potential.
Mirrored Target, while being useless as an active, grants 25% dodge chance and 60% Def and M DEF at max. If funded that is pretty significant.
Thief revamp holds very little for a DB compared to NL and Shadower, but the changes gives us maxed Venom before 4th job, a better HP% skill, Physical Training, a 30 att buff called Karma, and the old former DB exclusive ultimate Sudden Raid. Now if they just replaced Chains of Lol with something useful...
A heavily funded DB with unique/legendary potential'd gear will generaly faceroll bosses faster and harder than NLs. This of course is not taking into account illegitimate bullpomegranate equips such as enhance hacked weapons or high att VSS.

Cons
Low HP for a melee class.
Trains slightly faster than the other thieves early game, but the way MS works after BB, that aint exactly something you should pick your class based on.
The small range of Blade Fury will force you to stand on top of the mobs, if you have crappy avoid DEF and HP this will be annoying.
Weaker than the average thief unless heavily funded.
Expensive to fund because of theif popularity, and because they have 2 weapons to buy/cube.
Mirror Image/Shadow Partner nerf hit DBs the hardest beacue of how Final Cut works. A heavy blow, but no where near making the class low tier as some believes.
Most Kataras look like absolute trash. I am looking at you Blood Blossom.