no brush system is perfect
True...I'd say, though, for me Clip Studio, PaintStorm Studio and Rebelle 7 come incredibly close... (and just Rebelle for traditional, other than just picking some oils, acrylics or watercolors). As, not only is it the brush system. There are always other caveats coming with each app... Rebelle can't do large canvases due to all the physics calculations it makes. But nanopixel feature can help for print stuff and huge exports in general. But that's an AI enlarger, and I dislike the concept . At least that AI only invents micro fiber of the paper or oil canvas, to look nice on 300/600 dpi prints, it does not generate anything you did not paint; no scrapping. Clip Studio can't do 16bit per channel (smoother gradients and in general more intermediate tones, most people do not notice) while Affinity Photo (and Photoshop, I think Krita too) can. PaintStorm relies too much on GPU (so you'd better off having one, even a bad one, tho it can paint CPU-only). PaintTool SAI is somewhat limited in features (fully functional for painting, though).

I have PaintTool SAI 2.x, but... isn't it fully a raster, pixel based software? (no vector export? I wish I'm wrong...). I have it and it is indeed (by my personal tests) by very far the raster painting and image editing program allowing me to paint with largest canvases and largest brushes at the same time (in raster canvases). To very crazy levels. I don't have an idea of how the author was able to get that, it's like magic. It is the favorite tool of a huge percentage of artists doing commissions (many of them still use an old 1.x beta, I think), specially among students - artists, and some more pro ones who started in DeviantArt and now are quite pro. Quite a jewel. I believe the reason why it got used by so many young ones is because it runs on any potato, incredibly optimized for low hardware (besides being available as a free beta for some time). So, cheapo school laptops with no GPU (old intel's integrated graphics) would even work (as they do currently) with it even while doing big illustrations. And super fluid.

I had NO idea that Designer beta 2.5 was introducing that feature. As I don't check the beta forums anymore. I was a beta tester, indeed, but did run out of free time, sadly.

Still, that feature does not really fix the inaccuracy when laying down the stroke (actually the smoothing gets triggered once the line is finished, curiously it is accurate while in the process, the bad thing is in the unavoidable automatic post-smoothing).

You can work around it (till some extent...) by inking at very high zoom-in. Which might be fine as the key moment to see all the composition or most of it is when you are doing the "pencil work". But even so, while inking is very good to see all at once (or at least a 50% of the canvas) to check weights, etc.

I've never used Toon Boom.. I guess Moho Pro 12.5 (got it for like 20 bucks in humblebundle, like corel painter, totally legal, btw) will have to do for me for a while... or Clip Studio Ex/Krita's animation, hehe. I'm very noob at animation, anyway.