Editor recommended because this is the officially named Prestige Attachment for XR-3 ION. It is not labeled BEST. Tradeoffs are quoted from official launch copy.

XR-3 ION
MuzzleMFS 3x3 CompensatorReach maximum Weapon Level and Prestige the weapon.
A unique muzzle that provides unparalleled hip fire accuracy. This deadly muzzle increases the weapons charge time and harms aiming speed.
Attachments 1
- MuzzleMFS 3x3 CompensatorReach maximum Weapon Level and Prestige the weapon.
A unique muzzle that provides unparalleled hip fire accuracy. This deadly muzzle increases the weapons charge time and harms aiming speed.
Alternatives
- Base weapon / no prestige attachmentKeep the base gunsmith path if you do not want the official prestige tradeoff quoted above.
Evidence basis: Source
For streamers: add this as an OBS Browser Source — stream widget
Recommended · bo7-xr-3-ion-prestige-launch