Dead Man's Plate vs Sunfire Cape in Season 6
Dead Man's Plate
+500 Health +50 Armor 2800 Gold
Unique passive - DREADNOUGHT: Generates Momentum stacks while moving, up to 100, granting up to +60 bonus movement speed. Momentum slowly decays while slowed and decays rapidly while immobilized or silenced.
Unique passive - CRUSHING BLOW: Basic attacks (on-hit) discharge all Momentum, dealing +1 on-hit physical damage for every 2 Momentum discharged. If 100 stacks are discharged, damage is doubled to +100 and slows its target by 75%, decaying over 1 second.
Sunfire Cape
+500 Health +50 Armor (+5 armor in Season 6) 2700 Gold
Unique passive – IMMOLATE: Deals 26 - 43 (based on level) magic damage per second to nearby enemies (400 range).
Currently the small buff to Sunfire Cape makes this item a worm welcome to pretty much everyone who needs a tank and needs split pushing and/or 1v1 close combat. Sunfire cape will be super cost efficient, along with the "small" sunfire cape, that is Bami's Cinder. Even though it does less damage around you, it's more cost efficient and it helps you combat or split push early game against DMP.
Now for Dead Man's Plate. This item recieved alot of nerfs after his debut in Black Market Brawlers. It recieved a -100HP nerf, -5 armor nerf and a +50 gold nerf. Both have the same stats, aside from the passives. DMP's passive helps closing combat and does a few extra damage, and a small slow is helpful. But in split pushing, 1v1 close combat, and even close team fight, Sunfire Cape RISES and it's hugely better than the Dead Man's Plate.
TL;DR - In Season 6 (next patch), Sunfure Cape is a better item to get on your 1st/2nd buy. Dead Man's Plate can be situational now. Not to mention the 100 gold difference between both, the combine cost for Sunfire Cape helps who needs to buy it with less than 1000 gold.