Having gained experience with packaging in Ubuntu, Debian and Fedora my perception is that Debian and Ubuntu's policy of disallowing stable release updates for anything other than security and major disasters is their strength.
However, they can only maintain this strict policy without grinding to a halt because they have the mid-way point of Debian Unstable to filter out many of the bad eggs. For those not familiar with the paths packages take into stable releases for these distros here's a simple overview:
Debian: (Experimental)-> Unstable-> Testing (Frozen for releases)
Ubuntu: (Experimental)-> Unstable-> [Ubuntu+1] (Frozen for releases)
Fedora: Rawhide (Frozen for releases)
(I've parenthesised Experimental because it's not a necessary step, but is handy to use as a packaging sandbox. [Ubuntu+1] is named whatever crazy alliterative animal name Mark dreams up next.)
In conclusion, my intuition tells me that, due to the paths and QA points packages go through to reach stable in each distro, I should expect Fedora stable releases to be as stable as Debian Unstable. Maybe an ex-cosmonaut millionaire should come and base a new distro on stabilised snapshots of Fedora (I jest, I jest...).