Posted by: John Hudson
Joel: "Will SBL Greek offer features that Gentium does
not, or will it simply be another pretty and readable Greek font?"
As far as I know, Gentium does not support nomica sacra and non-standard accentuation (e.g. combinations of accentuation with metric marks). SBL Greek supports both these, using contextual overlining and dynamic mark positioning. Of course, Gentium is open source, so someone could add that functionality.