Again, you're comparing 0-star current 100% Eidolons to MLB 120% Eidolons.
Note, they're not going to be 140%-160% when they come out. They'll be 120% (or rather, 100% with no same elemental Eidolons) to 140% (or rather, 120% with no same elemental Eidolons). So rather than:
The question is more like "Would you rather have a friend with a 100% Eidolon or a friend with a 100% Eidolon with a a chance to be a bit more?"
Because that's what they are until they get buffed, which is what? 11 months from now?