I tried 8.0M1 the previous weeks (plain java source editing, no strange plugins)
but sadly had to stop to do so, because it became unstable after longer usage.
It happened to my coworker too, and it happened to me on two different machines.
The effects are eg that you cannot open a specific java source file into the editor (it just wont display),
or the commit project dialog takes very long to appear
or other generally strange behavior that I don't remember because it was so horrible that I now suffer from trauma ;)
No seriously: the thing becomes unstable and I'm forced to go back to 7 and I really hope you can improve this until 8M2.
Is it some cache problem? Is it already known? Or, better, already fixed? ;)