I use Corel Painter since version 9.5 and although there are many flaws and issues, I always come back to it. But there are two huge wishes for future versions I have:
1) Please add finally clipping masks than I can skip the buggy step to mask everything in a layer and add my watercolor brush splatters that than "bleed" through the masking edges. This bug adds hours and hours of extra working time to delete all of these overstepping watercolor white fringes:
2) Transparency issues: When I save my watercolor layers as JPEG or PNG they loose their transparency and have those awful white edges -argh!! And although efforts were made to finally make brushes that are transparent and act like Photoshop's brush engine they are not usable since they do maintain their original color. Instead they make those terrible color shifts. In the end I turned this feature off, since it was unusable.
3) PLEASE: Add a Pencil brush that is that effortless and natural like the Pencil brush in Apple's old version of Notes. The tilted shading is a dream and also the normal lines. It looks so realistic and beautiful. Also the adding color to brush strokes by layering them looks and feels very natural. Here are several examples for that:
4) Add tabs instead of windows for opened files please! Look at this fail - I cannot even read which file is which:
These are all great suggestions which I'd agree with. Tabs would be brilliant.
I also find it interesting that (for example, if I recall correctly) the "real 2B" while giving a great side shade when angling the pen has no grain interactivity... so it's wrongly named for a real pencil experience.
The pencil I keep returning to is actually the dull grainy CHALK, not found amongst the pencils at all.
As LeFAy mentioned, I also find it a problem that the watercolour bleeds outside of selections, even "preserve transparency" can't stop that white, creeping bleed if diffusion is being used.
Again, I've used Painter since IX- like LeFay, and I've always used whatever workarounds I can for some of these issues.
Both A highly realistic pencil ( an analog in every way, not just nailing one or two attributes but them all) and diffusion respecting the boundaries would be two tweaks I would consider fabulous PLUS+ PLUS!
the real 2B pencil also tends to mess up my colors adding unwanted hue/saturation spectrums that I never found a way to disable entirely (the typical painter color variation features were disabled for those), I suspect the problem is in the shitty way painter treats low-opacity soft-edged brush nibs, but it might have been a brush type specific bug too.
chalk brushes always much more predictable in their behavior, good suggestion.