Hi
Tried my problematic scene with Forest Pack object again with RC3 - parsing time now is much shorter, but it's still not totaly OK, I think. I rendered this scene again and again just pressing render - stop button and I got parsing time in range between 17 to 23 second, few times I've got 13 sec. In most of the cases parsing there was longer than 20 sec. Tried to do the same using build from 2016-04-24 - got stable 10 sec of parsing time
Tried also to render more complex scene (like the one on attached picture) with trees, bushes and grass scattered with Forest Pck. Parsing time is longer for about 20-25% than parsing time with build from 2016-04-24
BTW, what parsing time depends on? I thought that it depends on geometry, but now, making these tests I noticed that it depends also on light direction. For example parsing time for the scene which you can see on attached picture was more than 2 times! shorter in a case where sun light direction was perpendicular to the long walls of the building (forest_build_RC3_perpendicular.jpg)