In an effort to save on licensing costs I have just completed the migration from SLES to OpenSUSE. I have to say it was a little unnerving to step away from an enterprise class distribution. There were so many choices when it came to choosing the replacement for SLES, I knew we no longer wished to pay the licensing fee’s to only have access to software updates and support that has never been used (IMHO google for me is the best support agreement).
On the cards were CentOS, Ubuntu LTS, and OpenSUSE. Our main requirements were the ability to access upgrades and the use of an auto build system for rapid deployment. CentOS was ruled out early in the piece (unfortunately I have to say only for petty reasons, none of which are worth listing here). So the competition was between Ubuntu and OpenSUSE, now my personal opinion here would be for Ubuntu to be the successor but unfortunately it had a few fatal flaws.