Oh, weird, looks like the forum ate my reply with feedback. :(
So, here I go again, quickly:
1. Great update, keep up the great work
2. Found a bug:
Here you can see that the color swatch is "stuck" on screen after the sidebar panel has switched to the Selection tool properties.
3. When hovering the Selection and Transform tools, the popups can disappear under the cursor, and you can only get them back by moving the cursor out of the panel and back into it.
4. The option "Select this layer's alpha" is worded a bit confusing, I think. I expected it to select all the transparency of the layer, even though what it really does is a lot more useful. But maybe a change in wording would help here.
5. More Nitpicking: If the Selection or Transform properties are opened in the sidebar panel, clicking the "Show Brush manager" button does nothing "visible" - it just toggles the visibility of the Brush manager in the background, which is not really helpful. It would be nice if the button would first switch the view to the Brush panel, and only then act as a visibility toggle.
That's it!
EDIT: Actually one more feature request because the new >100% zoom made me notice this again: It would be great to be able to keep the brush size locked while zooming. So that when I zoom in close or zoom out far, the brush size always stays the same relative to the canvas size.