Yes, I am definitely getting less exotic drops as well; it is more than noticeable. I think Bungie lowered the chance for exotics when they introduced the 3 of Coins. When I do get an exotic, which seems much less, I almost always get an exotic I already have, so it just boils down to getting 5 legendary shards. I owned both Destiny games, and I feel like Bungie is playing a game with us. The 3 of Coins is basically a joke. They nerfed the chance for exotics and overall loot you get from public events down to almost nothing. The game has become a joke because Bungie is so stingy with what they allow us to get. I am so sick of the RNG game that they play with us. Every time I get an engrams I know I will just get more junk I already have. It has become a game that I really don’t want to play any more and almost seems pointless.
No, there are not complicated mechanics. Its a flat 50% increase. So if the base chance is .5%, 3oC brings that to .75%. Since we dont have base numbers, we cant really tell. But 3oC are underperforming in heroics. Just grab some friends with fireteam medallions and run some heroic p/es or cruicible. If you have the spare shards, up to you whether you want to use them or not.