Maybe it is just me and fellow workers in my office, but it seems to me that the 8.0.x release of PHPStorm is one of the most problematic in a while. There are a ton of things that broke between 7 and and 8 (https://youtrack.jetbrains.com/issue/WEB-13016 being an important one for me), as well as a bunch of the PHP Refactorings just don't work a bunch of the time (rename variable, inline variable, etc). You go through the actions and nothing is done (for rename this especially happens when dialog box is forced rather than the dialogless refactoring). It has also gotten slower, and hangs for seconds to minutes at a time all the time. I am planning on going back to PHPStorm 7 if this isn't fixed really soon (I would do it now, but every time I go back it breaks Unit testing and a bunch of other things in the project). Yes I have Invalidated caches, I even did a clean install and removed everything when uninstalling (I only backed up my keymap and file extensions and re-imported them). I don't know if anyone else is having issues, and there are a few reports in YouTrack but something like "invalid detection of local variable" which would have been elevated to high priority in the past sits there at normal with not a lot of activity in 6 weeks.
I've been using PHPStorm since version 1 came out and have had a license for 4 years, and this is the first time I am considering not renewing. It seems like the 8.0 version was released because it was time to release a version and not because it had been fully tested and was ready to go.
Maybe it's just me and my co-workers, but I felt I had to get the frustration of this release off my chest... Working with this product 90% of my work day, and having it freeze all the time removes the years of goodwill that JetBrains has acquired with my and my co-workers over the last 4 years of developing an amazing product.