Can you point to some of the instabilities?
DNS + a load balancer is proven and stable. We have 65,536 available ports on linux, and doing port mapping to prevent conflicts across containers is trivial (Empire handles this for us). Client side service discovery is usually unnecessary for most Docker use cases (stateless services), where a load balancer is a better fit (why push load balancing to clients? Would you expect your browser to have to load balance when visiting google.com?).
I'm sure there are cases where networking overlays are a good fit, I just haven't found one yet.
> I'm assuming you're referring to instabilities in Docker networking
I don't know... whichever instabilities you were thinking of when you said "If stability is more important than bells and whistles..."