Are there any compelling reasons to upgrade our application from Timesten 7 to 11 ? Is an upgrade really necessary ?It really depends. If your application works fine and you don't need a new functionality, you don't need the upgrade.
Also please let me know where can I find about "The features added in 11" and where can I find the difference between TimesTen 184.108.40.206.0 and 11.2.2 ?There is only one source of truth - it's a documentation
Is there any specific document that mentions about exact differences between Timesten 7.0.5 and 11.2.2 so that we can see what new features are available ?Have you had a look on the links I provided to you? There are a title "Changes in this release", so you should go the the following order:
(like for example Timesten 7.0 does not have PL/SQL support, but 11.2.2 has)