To long to read? The most played classes tend to be the easy to play classes or the ones that are good solo raiders. It's not class balance so much as it is class purpose.
wizard - 10
Ease of play: Easy - Moderate. Easy to play well, moderate to play very well, powerful damage, powerful support
ninja - 9
Ease of play: Easy - to Moderate. Solo tracking and PVP extreme, with lots of fun skills, second best solo raider class to..
dragoon - 6
Ease of play: Easy. Best solo raiding class with the highest amount of survivability and one of the best classes for sneaking into cities.
ranger - 13
So unused over the last map or so is finally a viable play. Easy to die if you get focus as taking damage while using grapple breaks it( as well as the fact that grapple needs to hit a higher location to be effective. Deadly in the back of a group fight raining arrows on enemies from a safe distance. Poor in lag still.
druid - 3
Ease of play: Moderate - Hard. Druid has some offensive abilities and great support but lacks mobility and is not the easiest class to learn or play while being rather a good class if you know what you are doing.
cleric - 1
Ease of play: Hard - Very Hard. Clerics have no offensive capabilities and no combat support other then their group invuln which can only be used once a fight. Their heals are by far the best in the game and used properly can turn the tides of a battle quickly. Although Clerics tend to have the best mana regeneration and a large mana pool they will easily use up all their mana in a large team fight so managing mana is very tricky and with the targeting of single target heals being difficult the life of a Cleric is appreciated but hard.
bloodmage - 1
Ease of play: Moderate - Hard. Blood mages can be powerful casters and can output a lot of damage, yet they are not the easiest class to learn how to control and manage their damage and skills. Definitely a great class, just not understood by most players.
disciple - 1
Ease of play: Moderate - Hard Disciple tends to be a hard class to play in a lot of fight scenarios as it's sorta all over the board with it's skills. It has several damage skills and several skills to manipulate players and these can play well, but at the same time since it's more of a jack of all trades type of class it often loses in 1v1.
runeblade - 2
Ease of play: Moderate Runeblade used to be used as much as Ninja, but with the current Ninja having track the runeblades have really fallen off the top tier even though they are still a very powerful class. Runeblades have a lot more in your face damage then it's counter part the Ninja as well as equal if not better mobility but Ninja's track and massive damage from behind has given it and edge recently in play count.
bard - 4
Ease of play: Moderate Bards tend to have a lot of mobility and a lot of combat options and group support. They were and even in their strange state still are good to have in group fights. They tend to be only moderately difficult to play as the biggest thing you have to pay attention to is their short buff durations.
beguiler - 2
Ease of play: Easy - to Moderate Beguiler tends to be one of the easier classes to play. With it's multiple forms of stuns and large AOE it's not hard to play a beguiler will and cause a lot of damage.
necromancer - 3
Ease of play: Moderate - Hard Necromancers have some great damage output but a chunk of it is damage over time, making the Necromancer a powerful foe, but one that has to do a good bit of kitting while his spells do their dirty work.
pyromancer - 2
Ease of play: Moderate - Hard Pyromancers have some massive melee/close range damage and burst out a lot of damage quick and then sustain with their melee. The problem and where the Pyro gets difficult is their limited armor and hp and their need to be in close proximity. With minimal mobility and low survivability in fights this class is often bypassed.
dreadknight - 0
Ease of play: Moderate The Dreadknight can put out some serious hurt and tends to be very tanky, but without good mobility they do not make good solo classes which drops the class down a couple tiers for most players.
paladin - 4
Ease of play: Moderate The Paladin can put out some hurting and tends to not only be very tanky, but also good team support, yet still without good mobility they do not make good solo classes which drops the class down a couple tiers for most players.
berserker - 1
Ease of play: Moderate - Hard. Berserkers can output a lot of damage and have some reasonable control methods to help them in fights, but most of their abilities rely on them taking a lot of damage which makes it difficult to try to get in and do the high damage while somehow staying alive. With a lack of high mobility this class is often overlooked.