Going to keep this one short and sweet:
Been playing at a 2200 level this season with multiple comps and different people in rated battlegrounds this season, seeing some different strengths and weaknesses in each form of play.
First off, your healing composition should look like this:
Holy Paladin, Resto Sham or Mistweaver Monk, Resto Druid
OR
Holy Paladin, Double Resto Druid
Basically, you want to maintain a holy pally for freedom, BoP, and lay on hands, very important in any CTF game.
Paladins, though susceptible to CC more than most healers, can bomb instant heals in open fight.
Now the important stuff:
Dotcleave -
Death Knight - Boomkin - Warlock - Warlock - Mage - Shadow Priest
Strengths lie in maps such as Silvershard Mines, Eye of the Storm, and Arathi Basin
Equally skilled burst cleaves will tend to out perform a dotcleave in a CTF situation
Death Knight should howling blast spam, boomkin should cooperate his AoE silence with DK's AoE grip and Shadow Priest's void tendrils and mage's frost nova.
Dotcleave can lock down an entire team and force trinkets/bubbles with instant cast, minimal effort cooldowns
Number one counter to a dotcleave is running with 2 resto druids and a well played shadow priest to factor in mass dispels. Your best friend is your spread distance in a fight.
Double Mage Double DK -
Death Knight - Death Knight - Frost mage - Frost Mage - Warlock - Hunter
High burst comp, high consistent single target damage.
Strengths lie in CTF maps and Temple, bursting down vulnerable targets and healers with minimal effort and maximum "faceroll"
Destruction Warlocks do insane chaosbolt burst, and when cooperatively fired off with DK and mage burst, nothing will survive, and CC prioritization seems to cease to exist.
Will have a hard time outplaying dotcleave in an AB, gilneas, SM, or EoTS unless your mages fire off PoM rings like champions to stop momentum and nab early kills.
Recommend attempting double holy pally to apply more freedoms for two DKs, with dispel nerfs this expansion you need to be passively protected from movement impairing effects if you wish to have more than a single DK on your team for melee.
General tips:
Pop cooldowns early, dont save a damn thing. Rateds, currently, are about gaining momentum and maintaining it throughout the entire match. Numbers most often mean everything in RBGs, and thus you must take note of the chart's numbers and identify ways to produce the highest possible damage and healing. When you begin landing kills and winning the fights, you must maintain control and momentum by staggering rez timers, taking advantage of geographical positioning, and communicating every important cooldown and CC chain.
AoE grips to frost nova to AoE silence or fear bomb
Instant CC is the only CC worth investing into this expansion.
ON RAIN OF FIRE WARLOCKS
obviously warlock's rain of fire is amazingly effective in it's procs and it's stun effect. But if you're breaking ring of frost and other CC, you're countering your team's effort. Try and aim rain of fire on top of melee and wizards that are out of place, but avoid using it on healers, and allow for the real CC to take place.
Please utilize this thread as a place to discuss these comps, and comp alterations or substitutes.