The new knife brushes in Brush 2021.7 are amazing. No more we get the strange uneven surface when cutting in. This can now be used as a true modeling tool and the resulting cute geometry is also very good and even.

This works especially well when using it in conjunction with dynamesh or retopology.

I was able to created this engine piece very quickly by using the knife brushes and booleans.

Throwing the model to Substance Painter with some fast automatic UVs gave me this piece.

Along with many other features, knife brushes are a must have. It is amazing to have decade worth of free upgrades.