Sorry, I really don't intend to be a " pain in the ****", but Krita performance is too slow, compared whith, for instance, 3.0-Beta-master-4a58260-x64.
I can paint normally with this version, at high resolutions without any delay on the strokes, but with both Cr releases, at the same resolution it becomes very hard to have the same results.
And when I use symmetry it's awful; seconds to render the other half of the picture.
Krita is not the same fast software it use to be; why, I really don't know, but this a fact, at least for me,

You're probably hitting https://bugs.kde.org/show_bug.cgi?id=363320 . It seems to be a recent regression and it's the highest priority bug on Dmitry's todo for this week. We cannot release without this issue fixed.

Thanks, Boudewijn

It may be the same problem; let's hope it can be solved soon, cause those CR releases are useless, at this moment. unless you work with low resolutions.