I was surprised to see how poorly strokes around the outside of text looked. Has this been reported before? I include a little example of what it looks like in the zip file. I did not look at many text types - my example is arial - easy to test others. FYI: Avenir was good many others (I have a LOT of fonts) were bad.
Is something not working like it should? Let us know.
This is actually new in Pixelmator Pro 1.6 — outside text strokes weren't possible before and we have added them in the most recent update. However, we're using the native macOS stroke system and it has some bugs like this one. For now, with fonts like this, you can convert the text layer into a shape, the stroke will look better because it will use our engine. And we will, of course, look into improving this in upcoming updates!