Esper Midrange is most certainly in contention for the best Deck in Standard. It put out a dominating performance in the recent Standard Qualifier Weekend on Arena. The Meathook Massacre left the format and playing to the board became even more appealing. Out of all the black midrange decks, Esper is the best at snowballing the game out of control. Curving out with Esper is nearly impossible to beat for any deck in the format.
Esper has powerful threats, great interaction and counterspells. I tinkered around with various approaches and card choices and came to the conclusion to not lean too much into either control or tempo and instead just play the best cards available at every step of the curve. Even then, this list is able to play both control and tempo very well.