When I support I play with spelltheif and I have to maximise it's passive (poking whenever stack come out). I take the risk to approach for a skillshot not guaranted to hit meanwhile the Janna with ancien coin on the otherside will gain much more gold than me for doing absolutely nothing. I feel like the maximum potantiel of spelltheif is even to a concurent with static reward.
Shuyin1782 votesPhreak went over the logic behind the support items and their gold generation in today's patch notes review. Pretty much, when you go Coin you are sacrificing combat stats. You get no damage and no tank stats. All you get is some regen (which during a teamfight doesn't really matter) and 5% CDR for when you go into combat.
Due to the trade-off of no real combat stats, Coin offers more gold generation. In addition, another trade-off Coin has is in its quest reward. Coin has the weakest quest reward due to having the fastest and easiest gold generation.
So in short, Coin is only good until you get into a fight or when you complete it's quest. After that it falls off when compared to the other 2 because its benefits outside of faster gold generation is next to non-existent.
Ahri Inari2 votesI did not see it that way. But the 15% mana regen in lane is not negligable making Janna both excel in sustain trade and disengage. An autofill can just pick Janna with ancien coins and perform good enough for 50% win rate because the nature of this combo highly reduce skill gap.
Shuyin1781 votesWell the 15% missing mana recovery got dropped to a 10% missing mana recovery with this patch, so that's a thing.
And Phreak went over the win-rates of champions like Janna and Soraka who naturally build this item. According to his research, the champions that should be building Coin (not Leona, Thresh, etc etc) didn't really have much of a win rate increase after the coin changes because the champions themselves were already good. So any fluctuation with win-rates in regards to such champions has actually been influenced by non-Coin related factors. But they did recognize Coin's value so they did nerf the mana, but like my previous post stated are the reasons why the gold went untouched.
Ahri Inari2 votesAncient coin + ardent censer. Yeah, indiviually ancient coin may not seem have high impact (from 52 to 57 in 5 patchs). But you can notice a notable increase in play rate, including people that are bad as support, while decreasing the average win rate, they get good result for someone autofilled. I'm glad to hear the item has been nerf this patch (I don't read all patches notes, there are too many).