Hello Tom,
I recently purchased the MU-2 and have been enjoying the snot out of it. I found a seemingly critical bug though tonight that was pretty scary in the finding (at night in the mountains):
The engine anti-ice is not working. On climb out, I got into moderate icing, and de-ice boots, props etc worked as they should. Engine Anti-ice though Was not working whatsoever, I ended up getting into a pretty scary 2000fpm descent before I set a manual key bind to toggle inlet head for the engines. I then got back stable and messed with it some, and the switches on the overhead definitely do not work. So for now, I'm using a manual key bind when I need anti-ice, but just wanted to post this for the next bug fix. Cheers!
Josh