My experience with Scala IDE 4.0 so far ....
Eclipse was my IDE of choice since I started coding in Scala. But things have changed now either of the IDE's have matured a lot (and equally).
Ubuntu linux has been my OS of choice , Iam right now using Ubuntu Gnome 14.04 it runs on GTK 3.12, the latest Scala IDE is based out of Eclipse Luna which have some issues i.e the select workspace prompt on eclipse boot appears but when you switch to any other app while leaving this prompt open you cannot go back with (alt + tab).
As you can see from the below screenshot that eclipse prompt is not dislayed in the desktop window overlay.
However this task keeps running on the background.
Eventhough I can be patient enough to wait for the eclipse to start completely after selecting the workspace I have a issue the below "force quit" prompt appears for several time. This is wher I got really disappointed.
(Note : this issue prevails in Kepler and Luna)
I have this issue for a very long time its the same reason I avoided Luna and used Kepler but Iam also concerned with Kepler support will be droped in the near future.
Solution
Easy one:- I picked Intellij IDEA Community Edition instead of Eclipse :)
Hard one:- I could also pick ENSIME but Iam not an Emacs expert :)