I have installed both IDEs on my Mac and use CLion on Linux. The code editor looks and feels obviously completely the same, however as App Code gives you easy access to nearly all features Xcode gives you (like profiling, iOS simulator…), for me it feels a bit more convenient for Mac or iOS App development. However on Linux, where AppCode obviously is no option I really love coding with CLion, for me it’s the best IDE I found for Linux so far.
All this is based on the context of JUCE based projects where project generation and management is mainly done through the Projucer and not through the IDEs themselves.
You can find my code formatting settings here, they are very close to the official juce coding guidelines (except for the fact that I haven’t found an option to prevent whitespaces before an empty pair of parentheses)