I have been using IntelliJ for more than 10 years and it is a great IDE. However, the past year it seems to be going a bit downhill in terms of performance and basic working functionality.
Some specific annoyances:
Sometimes the IDE just loses basic autocompletion features. One that often happens is, I start writing something like Map<String, String> map = new <hit autocomplete>. Here it does not list HashMap as an option. As I start to type it in, the IDE tries to force the wrong autocomplete options on me, and it is really hard to avoid having one of them auto-selected. That is, I want HashMap but it is not there and so it becomes a mess. Of course, once I manage to avoid the autocomplete with various painful exercises, it does finally find HashMap when I manage to force-type it in and hit auto-import.
Sometimes the specific classes in the package list become unresponsive. I might be able to click on any other class in the list and it is opened in the editor. But once a class in that list becomes broken, I cannot open it no matter how much I click on it. Go to class still seems to work. Only way to fix is to restart the IDE.
Sometimes seemingly random classes disappear from the package list. There is only empty space in the package list where they should be. Nothing brings them back but restarting the IDE.
Once I do one of these forced re-starts, the IDE starts to re-index everything. I would have though it already indexed it previously. Since I can have up to 10 projects open, the restart hits the CPU to 100% for 15+minutes for re-indexing.
And some more I am sure I forgot..
Most of these are too random to write a decent bug report. Yet I would expect the Jetbrainers to have similar issues and fixed these during the years or more they have been occurring. I mostly use the latest version of the Ultimate Edition on OSX.
So generally just saying it would be nice if there was some work put into making the basic features more fluent, improving the performance, etc.
Cheers & thanks for the great IDE..