My two cents. Logistic bots are evil only because they are not "realistic". In the sense that they occupy no space and so are collision free. And this allows them to defeat physic and achieve impossible throughput. You can buff belts as much as you like but they will never match logistic ...

I also got a crash (game freezes the computer) after a very short period of gameplay. As I really wasn't doing more than running on the map I suspect auto-save. First time I try 0.15 (with 0.15.10 version), I started a free to play map. I got a first auto-save that worked although not very smoothly ...