Thanks, I haven't seen that yet. It does look promising. I was vaguely aware that work was happening on these features, but I wasn't aware of their current state.
Unfortunately it doesn't look like these are available yet in Python, as Python doesn't seem to have bindings for QtQuick 2.1, at least based on my googling. Hopefully that will come soon though!
The limiting factor on pyqt5 is the internal binding to the v8 switch of qml. So when that happens, you will get native look.
While I see the benefit of using python for brevity in areas Ecmascript doesn't cover (file access, pipes, io, etc) I'd personally just write whatever scripts I was going to use inline with qml as js, because I already can assume v8 is running underneath the platform, and js is pretty fast, so think about it as an interim solution. You can actually write whole qml apps that never compile and just run on the qmlscene binary (which is just a shim frontend to the qtquickengine internals of qt to run qml files).
Unfortunately it doesn't look like these are available yet in Python, as Python doesn't seem to have bindings for QtQuick 2.1, at least based on my googling. Hopefully that will come soon though!