Good Gear Guide
In Pictures: Apple Mavericks - The good, the bad, ...
GOOD: Application Sandboxing
For organizations concerned about deploying deep OS use policies, Mavericks imposes sandbox restrictions on apps managed through the Mac Store. Although not mandated for users, as they can obtain apps from other sources, the sandboxing imposes constraints that have both limitations but also continuity among prior versions of apps built with sandbox-compatibility in mind. The sandboxing technique spawns an instance with its own user-account subdirectory, hidden from the user. The app instance lives in an isolated shell. Application isolation encourages developers to use the technique to prevent user-space from troubling kernel/machine space.
In Pictures: Apple Mavericks - The good, the bad, the upgrade