I think there needs to be a trade-off between bleeding edge and stability and I find that Gentoo tends to hit it on the head. I've yet to have the system break anything for me without explicitly warning me before hand, providing me a full mitigation & migration plan, and then requiring me to explicitly continue.
Arch has been pretty stable in the past but I've had problems come up numerous times due to the bleeding edge philosophy.
Point being that you should really only be going as bleeding edge as your community can reliably audit and provide support for. I think Arch toes that line most days and sometimes hops past the line. Gentoo however tends to stay a few steps back from the line and gets close to it but never actually steps over it. And then most other distros are sitting comfortably half a mile back.