I just wanted to share my perceptions of the current state of the plugin:
I think it's an excellent piece of work that is moving along quite quickly... thanks a lot to the team for making such a hugely important contribution to the Scala world!!!
Being a long-term IDEA user and switching many times a day between Java and Scala sources I am actually satisfied (for the time being) with the Scala plugins current feature-set. Of course there is still a long way to go to match the Java side of things in terms of feature-breadth, however, IMHO, all the basics are present and further investment in additional features should come after addressing the main three issues, that I currently see:
1. General Speed
2. Stabilizing the Compilation Server
3. Improving error highlighting
The main issue for me is speed. Being on a modern i5 machine with tons of RAM I am used to IDEA responding without noticeable delay to most of my actions on the Java side. On the Scala side I find myself waiting for IDEA many times a days for an considerable amount of time. General editor speed is quite a bit slower, things like highlighting or auto completion sometimes even take too long to be useful at all.
One thing I find quite annoying is the compilation server dying on me several times a day (either with exit code 1 or 143). Basically I have to go through the process of hitting a "scalac internal error", changing to the running pane of the compilation server, restarting it, and then triggering a project rebuild at least 5 times a day. In 3 out of these 5 times I even have do this twice because for some reason the compilation server did not properly initialize the first time. This really breaks ones workflow and probably should be a first priority fix.
When these two main issues are addressed I think the next thing should be to further improve the basic features (like proper inline error detection) before focusing on more inspections etc....
Generally however, IDEAs Scala plugin already makes development in Scala a pleasure.
Thanks again for all your important work!!