I want to quickly address performance. Yes. The game suffers from performance drops, however that is, from my experience, an issue with the game itself, especially on large maps the game is known to lack in performance. I tried the same save game both under Linux and Windows, and had the same performance issues, however they are not major, especially if you have decent hardware, however the general idea on forums seems to be, that RAM expansions can help, however I have not tried such things.