In 2005, Hyperion System 9 was released, and the world was... not impressed. While there were some neat centralizing of certain functionalities in System 9 like Workspace, Smart View, and Shared Services, the core applications were barely enhanced going into System 9. Planning 4 looks a whole lot like 9.0 Planning. Same goes for HFM. Essbase 7.1.6 is almost identical to Essbase 9.0 though there are some important enhancements to Essbase ASO.
9.2 fixed a lot of the bugs in 9.0 and it did add some neat functionality, but again, nothing was revolutionary. 9.3 (and subsequently, 9.3.1) added a lot of functionality. Frankly, it added more than the initial release of 9.0 did.
In July of 2008, almost exactly one year after Hyperion ceased operations as a separate company, Oracle released "EPM System, Fusion Edition" and the world was impressed.
Oracle EPM 11x was the most revolutionary version of Hyperion in many years. While all the products have been extremely enhanced, Essbase in particular was substantially enhanced to include text & dates inside the cube, attributes that change over time, and the new Essbase Studio product. Oracle even introduced a new application: Hyperion Profitability and Cost Management application.
Some expected Hyperion 11x to be bug-free, but with all the new functionally, there's no way it could have been. There has since been a patch issued for it, and at interRel, we do have clients adopting it, but it's still not as stable as 9.3.x. If a client bought Hyperion today, I'd definitely install 11.1. If a client wanted to upgrade from 9.3.x, I'd make sure that they wanted some of the new 11x functionality. If they didn't, I'd tell them to stay on the more stable 9.3.x platform.
Simply put, Hyperion 11.1 is the killer app that System 9 was supposed to be. It makes a very compelling reason for those pre-System 9 holdouts to finally pay their enablement fee and upgrade to 11x. If you haven't seen the list of new features, look on this blog and elsewhere, because you will be impressed.