Warhammer 40,000 – Raptors can be devastating when they can hit the right targets. Dropping in via deepstrike or just flying forward to get a jump on the enemy they're incredibly useful. Possessed marines don't have the randomness of old but a potential 3 attacks each at strength 5 is pretty good, especially with a 7" move. 

Warhammer 40,000 – Vehicles are so much better in 8th edition. The Landraider is the king of them all. A great save and giant guns make this monster a pain to get off the table. Troop Transports can harass the enemy after getting their cargo where it needs to be. Heavy support tanks like the Vindicator can be difficult to take out as they fire on the enemies equipped to take it out. The days of an all infantry force are at an end.

Warhammer 40,000 – Iron Warriors used to be something to fear back in the days of the old force organization chart having extra heavy slots meant a bunch of Obliterators coming down and wrecking face. In 8th edition they have the most lackluster of Legion Traits but one of the best relics. Regardless of how strong they are the color scheme is striking and makes for a good looking force.