I understand that the player's skill + their gear will be the two greatest determining factors.
That being said, I've settled on either M/P or P/W as my initial character.
Would someone mind offering-up some pros & cons for the two combos?
As I play M/P, I can offer pros and cons of the class. I'm capped on both sides.
Pros:
1. Holy Aura- 5 seconds of complete invulnerability to any damage, be it magic or melee. It has a 1 minute cooldown, but in instances and PVP, this skill can make the difference between living and dying. When paired with magic or melee immunity foods, survivability increases to 9 seconds, which should be more than adequate time in which to (a) run if you're not prepared to continue the fight, or (b) kill what/whoever it was that was trying to kill you.
2. Stunners: M/P has two of them. Lightning lasts for 10 seconds on players when maxed, 12 on a boss. The other is electrostatic discharge, which roots a player for 3 seconds. You must bear in mind that this will not stop a player/boss from using their skills on you unless you are behind them or to the side of them.
3. Silence: Stops all casters from being able to cast skills for 10 seconds on a boss, 5 on a player. Essential when fighting other casters/bosses with magic damage.
4. Outburst: Allows a Mage/Priest to triple crit on a target. Occurs about 25% of the time at max level, often boosting the Mage/Priest to the top of the dps scrutinizer. No talent points required.
5. Buffs: Include Elemental Catalysis (50% increased spellcasting speed and 20% increased magical damage, but has a 5 minute cooldown), Essence of Magic and Intensification (both of which boost magic attack power, one for 15 minutes, the other for 20 seconds), and Energy Influx (increases critical damage by a flat amount for 30 seconds. Others include Elemental Weakness (decreases Target's resistance to magic damage by 10% at level 65), Energy Well (reduces mana costs), and I haven't even covered the wind skills yet.
6. Nobody crowd controls like a M/P. Thunderstorm will take out a siege gate/defenses very easily at the top level. Purgatory fire is very useful for clearing trash mobs in instances. And as Electrostatic Discharge is a frontal AOE, it's useful for rooting small groups of players- provided you can move out of range before their skills fire off.
7. Urgent Heal: Saves like crazy on health pots/foods.
Very good solo class until KT, after which point you will need a group/guild. Depending on your gear, it is possible to hit a player for well over 90k health with a single fireball (although it has a 6 second cooldown).
Edit: Cons
1. Priest side can take forever to level up, even with the extra xp/tp boost provided by Xaviera at level 20/20. They're primarily a healer class and don't have many attack skills.
2. This game is going to starve you for talent points regardless of the class you play, so it is critical to pick which skills will best benefit your play style. As a m/p, maxing flame, fireball, and lightning are a must. After that, talent points should be allotted towards whichever side you chose to play (fire or wind). Fire and Wind Masteries are also a must-max, but cap out at 50.
3. As a mage, you are squishy. The bosses in the instances have insanely high magic crit resistance (and magic defense in general), and they hit hard. Annelia's adds alone can hit for 90k+ on a player (Grafu Castle). You must stat stam and some hp in order to be able to survive, sacrificing insanely high magic damage.
4. Mage gear is expensive. I'll say that again: Mage gear is expensive. It does not drop nearly as frequently as melee gear does.