It's true that current DIY users are getting a screaming good deal. Anyone who is not a current DIY user is missing out on a truly sensational opportunity.
In your case, as Derek says, anyone with Enthusiast is being uplifted into a whole new realm of power and functionality.
If I can paraphrase your situation, it's "In v4, I have a license called Enthusiast, and in CalMAN 5, I will still have a license called Enthusiast, so I'm not getting anything." Perhaps we should have called the CalMAN 5 license something more razzle-dazzle, to emphasize that it's vastly more powerful. You're getting color cube (3D LUT) functionality, just to mention one example, that was previously only available to professional colorists at a price of thousands of dollars. And lots more. So call it "Super-Duper Enthusiast With Technology Previously Unavailable in Home Theater," and see if it feels like more of a step up.
As Turbe says, you intentionally chose the downgrade from the Pro to the Enthusiast level. If you'd like to step back up to pro, PM me, and it can be arranged.
Anyone else with upgrade questions, please feel free to PM me as well. SpectraCal wants people to be not only happy with all the additional features and power they're getting in CalMAN 5, but ecstatic.