Ok,,, so we just went for ig3 and it went....
well! no big issues but minor things ofc. But i can tell you that it is a huuuuuge benefit of keeping the agile benefit of solving issues within a minute but still beeing able to do major back end fixes on a java platform.
The major thing right now is the increased speed of the admin interface, the tab switching speed and CSS theme that enables you to configure your CMS in any way you want.
Anyways,,, it was a smoothe ride from a oooooold version of ig so i can only recommend others to go IG3 too!