After working a day with the current EAP build i decided for me that it is not usable. I'm working on a small C# solution consisting of 5 projects with around 25.000 lines of code. While typing code the delay between displaying two characters on the screen is feeled a minute (but arounf 5 to 10 seconds in reality). The delay is caused by the intellisense functionality. If i disable R# intellisense the editor is fast as a lightning. I hope that the Jetbrains guys will publish a new EAP build soon with better intellisense.