Ok, last time I judged the Ubuntu distribution so hard, later I started to think if there are a perfect Linux.
First thing I believe is the Linux versatility, with the freedom of evolve or changing (forking) you can expect everything, so you can choice what to use as desktop, shell, editor, package system, ... Many distributions are open to change the default installation, or simply to allow to try any program in the repositories or just the code. The options are infinite.
I remember when you need to decide the parts of your system, in the beginning of many distributions the installation system ask you the packages to include, some times you obtain an unstable systems, but many times you have a personal system. Many problems could be resolved reading manual or asking in the LUGs, but some times you needed to wait until the next release and a programmer or hacker fix it.
Later the popularity of LiveCDs allows to install a full system which works fine, because many debuggers tested the system and the distribution try to support as many hardware as possible, now the user can add or remove the packages, and she does not need to configure the system, except for few simple questions. At this point the user can work and enjoy Linux.
Other part to discuss is the release time, the popular distributions are very active and release every 6 months (Ubuntu, Mandriva, etc.), other more wise wait the release is stable and functional (Debian, RedHat, Slackware, etc.), a third class doesn't believe in a release and you can rebuild the distribution anytime (Gentoo, Arch, etc.). This is an important fact to consider, because each release have a lot of bugs.
Besides, many programs are debugged by the people of the distribution, but other are not directly related and the quantity of available programs is very large, so the probability of something wrong is high.
Finally, the users are not equal, many people love Gnome over KDE, other prefer WindowMaker, another likes just the command line. Every one is right, because each one has particular preferences, impossible to satisfy all the world.
Conclusion: The Perfect Linux is the Linux you want, even if it has problems.