Mark Grayson's Earpiece usefulness?

The most recent Artifact tier list doesn't have the Earpiece yet, but I have a chance to grab it in the shop. What experience do people have with it, and what characters does it work best with? Currently have:

Robot - Medkit RR - Hologram Invincible - Body Enhancement

Also run Allen and Universal currently without artifacts who could use the Earpiece if it's worth it