Consider Moving More Commonly Needed Features from the Ultimate Tier to Lower Tiers
The Portfolio Management and Service Desk features are useful for teams of all sizes and not exclusive to large Enterprise teams. For example, I have a team of 4 developers that supports over 192 active repositories of code. Managing (in a Agile/Scrum way) these repositories as interconnected projects is difficult, if not impossible without the Portfolio Management features. Many of the Premium features are not useful or applicable for a team of my size.
Consider offering these features at the Starter (ideally) or Premium tiers.