Command: Flee, as Command cannot cause something that is directly harmful, should permit disengage and even picking a tactically advantageous way to run away.
Dissonant Whispers explicitly does not allow this.
In the 2024 rules there is no prohibition about causing direct harm. You can stand in the sunlight and Command a Vampire to "Approach" and he will come right into the sunlight and die on a failed save.
For the level, it is probably the most OP spell in 2024 (although Tasha's Laughter is right up there).
Its so OP lol.
At least its a wisdom save vs intelligence
Really Command and Tasha's Hiedous Laughter have really changed the game when it comes to multiclassing. It used to be that multiclassing a full caster meant losing substantial power WRT high level spells.
A 11 Cleric/8 Wizard/1 Ranger or 11 Sorcerer/8 Cleric/1 Paladin are substantially weaker in 5E than a single class Cleric or Wizard. Now with Command or THL they are ahead of a single class character in most encounters.
Command or THL upcast is usually generally powerful than most higher level spells if you have the number of enemies to target and the extra versatility you get with multiple spell lists, twice as many Cantrips, martial weapons and mastery while not losing any slots is a big boon.
As per Jeremy Crawford via X on 4/26/2016, Dissonant Whispers does not trigger Booming Blade. He bases this on the wording of Booming Blade that the movement has to be willingly and according to him, the movement from Dissonant Whispers would be forced movement. Now, his Tweets are not official rulings and the Errata says nothing in this regard and regardless, you can rule differently at your table.Whispers uses the foes reaction, so its immediate. Great for triggering party AoOs. Booming blade goes bang.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.