First of all let me say what a great application this is. I had been using DVDFab for a few weeks until I ran into about 20+ movies it just wouldn't rip. I came across your application and after a test run I uninstalled DVDFab. One thing that I noticed and it could simply be Windows vs. Linux and nothing to do with MakeMKV but the read speeds are different in each OS.
For example, in Linux, I can get speeds up to 8X, but with Windows it hasn't gone above 2.9X. Again, it could simply be the difference in drivers for the respective OS's but I figured I would post anyway.