The comparison table does a good job here. The only thing I would add is:
Partner API (EMIS) - this is covered under IM1 and is free, It often gets mistaken for the EMIS Partner Programme. You would rarely select EMIS Transactional API now in your IM1 submission. So I would call it IM1 Partner API. It’s being rewritten for EMIS-X too: Authentication | Partner Developer Documentation.