That’s sure that interface is not “classic” and can be confusing.
But once you get used to the interface, Inkscape is really more powerful than Krita for vector drawing.
For me for example, Blender’s interface is more confusing than Inkscape’s one.
I suppose this is relative to each users, their habits, their workflow, … 
Concerning vectors, I’m just not able to use Krita’s vector tool like I do with Inkscape.
On my side, I use Krita’s vector layers for small&quick things.
If I need to draw complex or precise things, I use Inkscape.
But I really appreciate the possibilities to include vectors shapes in Krita’s document and be able to made some modification on them 
Concerning stability, since version 1.0 under Linux I find it more stable (didn’t tried windows version)
Grum999