I made a thread that is dedicated to the numbers and facts about the items strengths here:
http://boards.na.leagueoflegends.com/en/c/gameplay-balance/LVoKbnL7-redemption-analysis?comment=00040000
Here is the copy paste:
Redemption analysis for some understanding on the item and its state in the game complete.
Im seeing a ton of Redemption hate and I think some people are confused about why they think its overtuned, or overpowered. Im going to breakdown the item here so people can understand it better and what theyre up against concerning this item.
Many people have complained about the shielding it allows. Stop. The shielding bonus isnt the problem, it adds 10% shields/heals as do other items.
Lets look at Karma:
Her E shields for: Shield: 70 / 100 / 130 / 160 / 190 (+ 50% AP)
Thats 190 at rank 5, with 10% extra its 190+19 = 209
So Karma plus Redemption = a 209 shield. How about we compare that to another item that is good on Karma?
Yeah, it also gives the 10% shields/heals passive. It also gives 60 AP.
So Karma plus Ardent Censor = a 242 shield. That is 190 + (50% of 60 AP) = 220 + (10%) = 242
Its MORE than Redemption. No one was complaining about this all last season... because it wasnt a problem. Shielding people isnt the problem. It just isnt or people would have been rage circle jerking about it last season in rage post on the forums. Further more, 
does 20% heals/shields, gives MORE HP/mana regen than Redemption does, gives 10% CDR, and lets you use a cleanse effect on your team, and cost the same. It dose a lot of the same stuff.
Now that we covered that, lets focus on how similar and 
are.
NO ONE! No one was complaining about Mikaels . Doing most of the same stuff, and having a free summoner spell active.
Now as for being overtuned, it may just be that other support items (often to keep them from being bought by other roles) are just badly undertuned. cost the same, does a lot of the same stuff, but is 66.51% gold efficient without its passives, and cleanse active. on the other hand is 92.06% efficient without its passives, or active. Support itemization is straight up crap people! Remember the 
nerfs cause it was both cheep and effective for mid laners? Yeah, support itemization is bad to avoid this.
So having covered the much better gold efficiency of Redemption, there is about 8% left over for the value of its active/passives. Since its passives are both weaker than Mikaels (its mana/health regen, bonus shield/heal passives) lets just say that the remaining 8% is the value of the active. Its more complicated than that with the way Mikaels health/mana regen work, but for simplicity sake lets not go into it.
The active for Redemption is:
Target an area within 5500 range. After 2.5 second, call down a beam of light to heal allies for 150 - 490 (based on target's level), deals 10% of maximum health true damage to enemy champions and 250 true damage to minions (120 second cooldown).
So every 2 minutes we can AoE heal for 150 - 490. That is a lot and its at the value of 2100 x 0.08 = 168 gold.
150 - 490 healing for as many people as can be in the AoE every 120 seconds vs 
(90 - 345 healing for 2 people) and a short speed boost every 240 seconds for 168 gold. This is on top of the 10% max HP true damage. I dont think the damage part is super significant, it takes 2.5 seconds to go off and has a clear indicator. What we really get is a half cooldown time, stronger heal spell, with a delay for 168 gold... thats pretty good.
So this is where we are with the item.
is a much more gold efficient with a better summoner spell active and HP instead of MR.
Final analysis is that it may be a bit too strong. NOT because its gold efficiency is much better than other support items, but because the active is way to good for the remainder gold cost.
While I like the item, and am very happy Riot is putting in some good support items I think the first step with Redemption should be to remove the needless power of the enemy true damage (lets face it, were using it for the heals over the damage) and to lower the healing a bit. Some things that could be done is to spread the healing out i.e. divide by the number of targets. Or maybe just lower the amount of healing at higher levels to 375 maybe. Not sure exactly, but here is where the discussion can start, we have the information and tools to talk about Redemption.
Please share your thoughts on . Do you think supports need this because the game needs supports? Or do you think its just a wee bit too strong, or do you think its OP af and needs to be deleted? Curious what you guys have to say, thank you for reading.
comboed with 
tilts the hell out of me.
