Damn, no response?
I really wanted to play this game but I guess I just can't.
I'm sorry, I am unable to check comments 24/7...
I have no idea about what could cause slowdowns on your system. The specs seems more than adequate.
I tested the game on a 2012 win 7 pc with a 2.2 Ghz i7 and it runs without issues.
I also tested on a GPDwin2 whose specs are inferior to your system and I experience no slowdowns as well with no need for /MIS1 commands
Try to see if there are too many processes active on your end that may affect the game's performance
I should have been more patient. Anyway thanks for replaying. If I find a solution I'll let you know about it.
Edit: Something about manually moving the files to a different folder will cause slowdown or it was just a bad extraction. Extracting again was all I needed to do. I'm playing at full speed now.