This die has the same amount of material missing from each side. It makes this die more balanced than regular dice. In theory. ;-)
Update: some users tested the first version of the die for fairness. Turns out: it wasn't very fair at all. This could be caused by the rounded edges amplifing any imbalance. So, the new die, version 2, has sharper edges.
I've tested the new version and it seems to perform much better. Also, the rotated print gave better results than the regular one did. See the comments for more information on how others and I have been testing the dice.
Created with Tinkercad.