Adobe has disclosed that Photoshop CC suffers from slow downs when run under OS X 10.11. The Image Size preview is also broken. They are working on a update to address both issue, and have temporarily posted workarounds at https://helpx.adobe.com/photoshop/kb/photoshop-and-el-capitan-mac-os-10-11.html

>>UPDATE: The OS X 10.11.1 update fixes this issue.

Adobe is recommending that Audition CC users refrain from upgrading to OS X 10.11 at this time, due to crashing with plugins and native effects. Many audio devices are also non-functional because updated drivers haven’t been released yet. http://blogs.adobe.com/audition/2015/10/audition-cc-and-osx-10-11-el-capitan.html
>>UPDATE: The OS X 10.11.1 update fixes this issue.

Adobe has disclosed that Premiere Pro CC suffers from instability when run under OS X 10.11. They say this issue will be resolved in the next major release. For now they are recommending El Capital users change the playback engine to CUDA or software only (located in Project Settings). http://blogs.adobe.com/premierepro/2015/10/premiere-pro-cc-and-mac-os-x-10-11-el-capitan.html