After I noticed a router bit would dig slower and leave burn marks at the bottom surface, I tried to clean it up, but nothing was stuck on it. So I used a better tool to look at it closely an to compare with an (almost) new one.
Both are the original MaslowCNC 2 Flute compression bit, a special custom production.
These are the side view of the cutting corner. Note the scale reference.
You might ask how long the left bit it lasted? I can’t say really: It might have lived longer if it did not shave the top of a metal screw 
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