Right now it seems like everyone in every class can get 45% CDR with little to no real draw backs.
I few great examples are: 
These items would be good even without the CDR, yet for some reason they have it... I believe that CDR should be a significant or at least noticeable trade-off for other stats. Right now everyone just gets maxed out as if that's supposed to be balanced or something.
ModWulf Helhammer10 votesCommunity, pre mage rework: "we need more CDR options!"
Riot: "Ok! We revamped some old items and added some new ones so you have more access to CDR now!"
Community, now: " RIOT! WTF is all this CDR? You need to get rid of it now!"
Riot: "..."
ChaddyFantome5 votesMeanwhile as a Support, we have TOO MUCH CDR to the point where we over cap on the stuff regularly and waste stats on purchases. :/
already 45%... =.=
..yea screw those now because lol 2much CDR. Gimme some AP or MR or Armor or anythign else instead D;
ABlueQuaker1 votesMaybe change Athene's to 10% CDR. 
has been my go-to build all season.
ChaddyFantome1 votes[{quoted}](name=FA Quaker,realm=OCE,application-id=3ErqAdtq,discussion-id=W6iipVRP,comment-id=00030000,timestamp=2016-10-15T13:03:25.165+0000)
Maybe change Athene's to 10% CDR.
But Athene's haing 20% CDR is important for Utility Offensive mages like 
. The problem is not every other item needs CDR on it.
Why does 's Have CDR on it at all?
Why does it build out of 
?
Make it build out of 
Imo. It makes a much cleaner build path.
I imagine you play 
or alot?
I play mostly 
, 
, 
, , 
, so feels redundant most of the time and takes too long to build.
My build has mostly been , , , , / , 
Ben Sharpio2 votesno i want CDR
LatetotheRace1 votesYou can have CDR, I'm not saying you can't. What I am saying though is that there will be a trade-off. If you want that 10% cdr, you may have to give up 30 armor, or 200 health or something else similar. As it stands, it's just a tag onto many items that already have strong stats otherwise.
AirKingNeo2 votesCleaver is fine having 20% CDR, it needs to be melee only so ADCs stop abusing Bruiser items. Ghostblade is fine, it's 10%. Protobelt is fine, it has other problems and CDR isn't one of them. Hourglass and Abyssal are fine CDR wise, Abyssal has other problems. No one builds Warmogs. Sheen needs to be reverted so Trinity doesn't give 20%.
Ahristocats1 votes should keep the cdr and get its attack speed deleted
it was an item built on caster, not on adc.
Unironic SJW1 voteswould still first buy it on MF if you flat out deleted the ASPD with no compensation.
Ahristocats1 votesthat's because mf can make use of the armor pene like an ad caster with her ulti
but she would be worse in 1v1 with an other carry like jinx if jinx rushes IE/a carry item.
NervPursuit1 votessheen doesn't give cdr
Irelia Bot6 votesyes it does http://leagueoflegends.wikia.com/wiki/Sheen
250 mana 10% CDR 100% base AD on hit after using an ability
I would not mind it losing the 10% CDR for 5% movement speed.
All Skillzz2 votes[{quoted}](name=Irelia Bot,realm=NA,application-id=3ErqAdtq,discussion-id=W6iipVRP,comment-id=00020000,timestamp=2016-10-15T06:24:27.162+0000)
yes it does http://leagueoflegends.wikia.com/wiki/Sheen
250 mana 10% CDR 100% base AD on hit after using an ability
I would not mind it losing the 10% CDR for 5% movement speed.
no sheen is my early cdr item for ap ezreal.
Irelia Bot5 votesgo cry me a river
He bought sheen when it had 30AP with no CDR and he would buy it after such a change as this.
Asayake 5150glow2 votessheen doesn't give cdr
Does now. No AP, either.
LatetotheRace1 votesGuess you've been out of the loop for a bit mate.
Asayake 5150glow1 votes has to keep it's cdr, or else goodbye 
Same with Ghostblade too.
Why exactly does Morello's have 20% cdr? I mean... seems a bit overloaded, tbh. Also why Grevious Wounds? That's not the main reason people buy it (especially since it's also only below 30% health)
MunchCrunchLunch2 votesand is that a bad thing.
DemoGuide1 votesI believe some AD items should lose a bunch of CDR. Or we can go another way around and double cooldowns of all ADC's, at least on mobility spells.
LatetotheRace1 votesThis is a big reason I've looked into this. As it stands, there are several AD fighters top lane who can build + the cdr mastery to get 40% CDR after only 1 item and t2 boots.
Fairyfleur1 votesIf you remove the cdr from Zhonya's it will have been outright nerfed since its change in the mage update. It's built for utility and it should stay that way.
SwiftKitten881 voteshome come out of all the items u listed cdr is only on issue on
yet you dont even bother to list or 
?
LatetotheRace1 votesWell you're right about trinity, so I'll add it. (I was writing it in a hurry before work) However essence reaver, as good as it may be, no one builds.
SwiftKitten881 votesWell you're right about trinity, so I'll add it. (I was writing it in a hurry before work) However essence reaver, as good as it may be, no one builds.
again though, some other item you listed are NOT an issue, yes support can easily get 40% cdr..
but either needs to to keep its CDR or get its AP back
got crazy nerfed, -50 AP + 30 longer cooldown -5 armor , all for 10% cdr and 400 less gold?? no thanks...
, i think 20% may be overkill yeah i would consider lowing it to 10.. but it wouldn't be a huge issue if wasn't also used with it
with the change to make worthless to every mid laner who previously built it, this is the only MR item we have left that even provides offensive stats
LatetotheRace1 votesI 100% agree that Zhonyas is not really good right now, and I think it needs to be reverted from last season.
I also agree that 10% CDR on and is a much more balanced state.
Abyssal scepter is a strong AP fighter item, which if you want the resistances coupled with the damage and mr reduction you have to pay for it. That payment is of course sacrificing other cdr options. Rito just said F@#* it and did whatever.
I don't have any idea why Riot reworked Athene's, but I think that would be fine IF they had added new items. A big one we're missing right now is a MR and mana item, but for some reason they've been quite reluctant to add it.
Blkninjar871 votesI honestly wish there were more 5% CDR Items.... especially for supports its so easy to reach CDR ur forced to buy offensive/defensive stat items.
FantasySniper1 votesMages really needed the CDR, but stuff like this makes less sense;
Has too much for supports, they already have CDR coming out the wazoo.
AD Caster/Bruiser super-item.
AD Caster/Bruiser super-item Mk. 11, now with attack speed!
Ezreal is literally the only one that buys this.
LatetotheRace1 votes"Mages really needed the CDR" Sure, but there's literally 0 take away right now.
"as too much for supports" Eh, supports can have free CDR their other items suck anyway.
Screw the stats on this thing, it's far too stronk and we pretty much all know why. (attack speed + fighters = cancer, and the easy 20% cdr.)
"Ezreal is literally the only one that buys this."
Have you looked top at all? Yes, it's not as popular since EZ had it nerfed pretty hard.
All use Iceborn pretty well. (2 of these champions use it because I do, guess who.)
FantasySniper1 votesEzreal is literally the only one that buys it.
It can't compete with a Sunfire Cape rush, because it has minimal tankiness and damage output compared to the health and Immolate passive. The CC is also area-dependent, so it's wasted on most anyone with an actual escape. It's a late-game item for armor stackers much in the same way that Thornmail is because its only value is in the AoE which needs armor to scale.
If you're rushing it on anyone that isn't Ezreal or Malphite, you're gimping yourself. Maokai and Sion are the next best users, but even they have little reason to use it over Sunfire Cape.
Lugg1 votesThe problem isn't the CDR, the problem is very strong abilities that have ridiculously low CDs. The Fizz troll pole and Lux ult are perfect examples.
Irelia Bot1 votesGive Sheen 5% movement speed in place of it's 10% CDR. This in turn results in higher movement speed on trinity say 9% and lower/no CDR if stinger were replaced with recurve bow.
Black cleaver could stand to have slightly higher AD and health at the cost of 10% CDR.
Would rather see warmogs build from 2 Giant's belts with 1000 health instead of 10% CDR.
Ghostblade is fine as it is. 10% CDR is not breaking it as an item.
Proto belt needs to have a longer cooldown on the active at least.
Abyssal could be reverted to what it was.