First lets just look at things RAW, if we add magic items into the mix this discussion will never end. for every magic item/splat item/splat spell you give Clercis or Druids, I can give the other classes as well (heck I cab give wizards two for every one you give me!). Lets also ignore PRc's for now, simply because any PRC you toss out for COD will have to come up against Ultimate Magus, Raumathari Battlemage, Eldritch Knight, etc etc. That will not be a pretty confrontation for CoD. 
Ok:
Disintegrate beats Harm any day for the simple reason that harm is a touch attack that requires the CoD to go into melee, while the Wizzie can disintegrate from a ways away.
Firestorm is lower level than Meteor Swarm, and as such MUCH more prone to Spell resisitance. Meteor Swarm Wins.
Wizards have a ton more spells they can maximize to far greater potential.
Mage armor , shield and magic missile. CoD has nothing on these. Nothing. Do not underestimate thepower of the duration of Mage Armor, and the power of lower level spell slots. (i.e. wizards have a ton of lower level slots for these 3 babies)
CoD has to focus on many stats to be effective at casting and melee. Theyneed high str for attack/damage, high con to survive in melee, his WIS for their spell DC's, and decent Dex for Ac boost. therefore they end up being not much good at anything.
Wizard only needs high INT. Wizard wins.
Wizards get power word kill, along with the other power words.
Wizrds have more feat slots to spare for item creation, spell focus, spell penetration etc, especially since they already get meta feats for free. CoD though has to split focus from martial feats (wepaon focus, cleave, power attack etc) to their divine feats, metamagic feats, item creation feats etc.

Ok:
Disintegrate beats Harm any day for the simple reason that harm is a touch attack that requires the CoD to go into melee, while the Wizzie can disintegrate from a ways away.
Firestorm is lower level than Meteor Swarm, and as such MUCH more prone to Spell resisitance. Meteor Swarm Wins.

Wizards have a ton more spells they can maximize to far greater potential.
Mage armor , shield and magic missile. CoD has nothing on these. Nothing. Do not underestimate thepower of the duration of Mage Armor, and the power of lower level spell slots. (i.e. wizards have a ton of lower level slots for these 3 babies)
CoD has to focus on many stats to be effective at casting and melee. Theyneed high str for attack/damage, high con to survive in melee, his WIS for their spell DC's, and decent Dex for Ac boost. therefore they end up being not much good at anything.
Wizard only needs high INT. Wizard wins.
Wizards get power word kill, along with the other power words.
Wizrds have more feat slots to spare for item creation, spell focus, spell penetration etc, especially since they already get meta feats for free. CoD though has to split focus from martial feats (wepaon focus, cleave, power attack etc) to their divine feats, metamagic feats, item creation feats etc.