Yesterday I've finally updated my server from Sarge to Etch (around 300 packages to update, 100 newly installed, 15 to remove). The whole transition went smooth in a screen session in about 4 hours or so.
- I began with a normal upgrade as suggested by the release notes.
- The next step introduced the new initrd-tools and libc6 to the system ...
- ... followed by the installation of a new linux-image and udev.
- The last step in updating the packages involved a complete dist-upgrade.
- Then it was time for a reconfiguration of all the services, that installed massively changed config files  and fixing all the chroots and broken package configurations caused by package transitions.
- The reboot brought up the system at first go. Checking with dmesg and bootlogd did not show any serious issues: /dev ok and all services up and running with the new kernel. So besides a few modules, which are not longer available or changed their name, no issues occured.
- With the new system up and running I did some cleanup, removing unused packages and those, that were removed in Etch (all together around 25).
That's all. New system up and running (with a few configuration works left) and no need to restore the system from the image :). So yes, I'm satisfied. Let's see, if issues will occur later.
 In this case I installed the package maintainers version and re-added my changes later.