Ok, pros and cons. I think this should be somewhat fair:
Wizard has low defense, average attack, high mobility. Wizards and Dragoons have the highest mobility in the game. This is their primary benefit, giving them a fair chance in pvp. Unlike Rangers, Wizards have 3 instant damage skills which allow them to keep moving and kite their opponents. Fireball and Iceball are skill shots, providing an incentive to become skilled at aiming, similar to Ranger; however, they can keep moving as they make these skill shots. The ability to move and attack is very useful against players. Mobility isn't a big concern against minions though, as nobody has a problem escaping them; however Blink can be useful to escape when surrounded. Wizard's average attack means that it can't take enemies down very fast, and must instead rely on its mobility to stay alive with such little health. In pvp, this means Wizards become a frustrating opponent to melee players who must chase it down to do any damage. Dungeon elites and bosses will easily kill even the most proficient wizard because mobility doesn't help against teleport and forcepull, meaning wizards must rely on party members to aggro elites and bosses at all times.
In a dungeon party, wizard's average attack can be somewhat useful, but its primary benefit in a party is its ability to bypass mob invincibility. Because all of its attacks land, wizard is a reliable damage dealer in isolated boss fights with large parties, such as the golem boss when lured onto the grass. However, in most circumstances, wizard will occasionally aggro a mob, and must run completely out of range so a teammate can take the aggro. This is viable in some spread-out dungeons where the wizard can flee to a safe location, but in Ivory City, Sky City, and Desert Town, there's nowhere to run without finding more mobs.
In pvp, a skilled wizard is able to avoid taking damage from the enemy through maneuverability while inflicting damage at a short distance. In dungeons, maneuverability means nothing and the wizard is easily crushed because it cannot kill mobs faster than the mobs can kill it.