We havent seen serious changes or new mechanics since Locations were introduced in set 3 Into the Inklands
Unlike past years, where much of the value of the decks was tied to reprints, Commander 2018 is all about the new cards, which pushes the Esper deck to the top of the list by a decent margin, thanks mostly to Yuriko, the Tiger's Shadow being the most expensive card in the set but also some other solid-value cards, including Sower of Discord, Geode Golem, and Varina, Lich Queen
Bolass Citadel can enable some broken stuff in any mono-black deck, especially one focused around artifacts
You can exchange Hunter's Prowess for Descent into Avernus pretty easily, which also reduces the overall mana cost of the deck
This is a matter of taste