When should I upgrade to the newest Sugar?

[anicolais]

Currently I have a client running Sugar 5.5. I really like the new email functionality in 5.5.1 RC2 but I want their system to remain stable. When should I update their instance? Is 5.6 the next stable release?

[kuske]

My personal experience is that all patchlevels e and g are stable.
So at the moment you should use the maximum version 5.2.0g

Sorry that sounds hard, but fact is that each new major release brings new code and new code brings new bugs. That can have bad consequences in daily used production environment.

Each new release should be tested very intensively before releasing it to your users.