Salix 13.0.2 installed in 2009 and upgraded to 13.1 in June 2010, this included a downgrade after initially leaving out the kernel and mesa-libs which resulted in choppy screensavers and no GL acceleration. After deliberating, I did a full upgrade and arrived at the expected result.
13.1 ran fine here until last month, June 2013, when I decided to upgrade to 13.37 and straight from there to 14.0. Again, no issues were encountered. All one has to do is stick to the excellent upgrade instructions in the wiki, so effective and simple my cat could do it. I really recommend the User documentation and FAQ sections on the documentation hub.
Last but not least I attempted an upgrade from Salix 14.0 to Slackware-Current, which did not entirely work out due to many changed packages but left me with some original Slack artwork for the LILO boot loader. I downgraded back again to Salix 14.0, except the kernel which is now regularly updated from current and is currently 3.9.7 here.
So let's see. That is five upgrades and two downgrades and the system has not only survived, it functions well without any odd hiccups here and there and runs fast (I cleaned out some old cruft, residual configs, leftover folders of uninstalled applications and such). I do all sorts of multimedia work incl. connecting and importing from digital cameras, using a very old Labtech webcam with a known service and on hangouts, the usual web and office work, a lot of research and writing these days and the occasional compile. The latest Oracle VirtualBox (official package) compiles its kernel modules as happily as the rt5370 driver on SlackBuild.org for the iffy Realtek wireless USB adapter (It's an old motherboard and none of my desktops came with onboard wifi, hence several of these external adapters).
Great stuff, and although not wanting to cause any distrowars, not even Debian has achieved such a feat for me so far. Not to mention other distributions that break at the faintest attempt of upgrading to the next version. Obviously we can't really count rolling distributions in this as they're not designed to be downgradable, although with Arch one can keep old packages local or search back in time mirrors, but it's not what the distro is about.
I can't say it often enough, it really pays to read and follow documentation. Thanks to Salix and to Slackware for keeping it clean, nice and the package format simple. It just works.
|Salix 14 Xfce with a somewhat Gnome2 like layout, top panel hiding.|