Here's another data point. I've been using Red Hat since 6.0 (and later RHEL and Fedora). I have used CentOS in the past. This is the first time ever I've heard

Here's another data point. I've been using Red Hat since 6.0 (and later RHEL and Fedora). I have used CentOS in the past. This is the first time ever I've heard about Scientific Linux. Also, none of the VPS services I use support it. They all support CentOS. What I'm saying is that it's really not a a "mainstream" distro.