Hi Guardians,
Soon after the 3-of-coins became available I started keeping stats on what I received from them. 
(@ Nov 29 2016)
  	          Before ROI	    After ROI			
Primary	        11.5%		10.0%
Secondary	19.4%		12.0%
Heavy	 	11.5%		  8.0%				
Helmet		18.0%		12.0%
Gloves		  7.2%		18.0%
Body		10.8%		  6.0%
Boots		21.6%		34.0%
					
Weapons	42.4%		30.0%
Armour		57.6%		70.0%
I seems a few things changed in this area with the Rise of Iron expansion.  Weapons are less likely to drop than before, boots seem to be the most common item dropping (before and after the expansion).
Hope you find this interesting.
Regards
Eric
						
					
					
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	3 RepliesYou would need to have thousands of engrams to get a proper gauge on actual drop rates and probably input from many players. Considering you're still working with even percents in RoI, I doubt that is there. I for one have gotten a shitload of special weapons since the release of RoI. It makes sense that armour drops more than weapons considering there are 4 armour engrams and only 3 heavy (which actually works out to your TTK percentage). From this, it's still perfectly possible that each of the different exotic engrams has an equal drop rate which I'd say is more than likely. The way this game has worked with its loot tables, I'd say it's perfectly likely that it's totally RNG that selects equally from among each of the exotic engrams in the table.