I’m working on Mac most of the time and use AppCode there. When needing to do work on Linux I use CLion there. The look and feel of both IDEs are quite similar, so I immediately feel “at home” in both IDEs, however for Mac I see no benefits in choosing CLion over AppCode. I like that one can switch to Xcode from within the same project if you need it for some reason and that tools like Instruments are directly integrated in AppCode like they are in Xcode.
Personally after having worked a lot with AppCode, switching to Xcode always feels a bit bad because AppCodes auto completion and code diagnostics just work soooo much faster and better and I feel much more productive in the AppCode UI. But as always, that might be a matter of personal taste.