You can compare this to what I believe is the state of the art system, "Wetbrush":
https://www.youtube.com/watch?v=gwyqh4d-WU8 (SIGGRAPH Asia 2015)
https://www.youtube.com/watch?v=k_ndr3qDXKo (Adobe demo)
https://www.youtube.com/watch?v=gwyqh4d-WU8 (SIGGRAPH Asia 2015)
https://www.youtube.com/watch?v=k_ndr3qDXKo (Adobe demo)
http://www.painterartist.com/en/product/painter/
It's been around for about 25 years and some of the UI is a bit creaky, but on the upside, it's pretty fast on modern desktops and it still gets regular updates. Brush strokes with 3D depth ("impasto") were introduced a long time ago, maybe late '90s.