Only just discovered this distro, it seems as if it might make a good server OS. Any thoughts on this, is Mageia likely to be a good server OS or should I just stick to CentOS for servers?

IMHO "likely" and "good" aren't the criteria to use as it could easily lead to only opinions. Since it's about servers instead: a IMHO better question could be: "is the distribution or upstream known for providing a server class / Enterprise-grade Linux distribution?" and the criteria to apply could deal with vendor experience and commitment, quality assurance, distribution longevity, sources of support, state of the documentation. Comparison should result in a list of "must haves" which could then be compared with a "like to have" list of features you're missing. If any of those are crucial you have a valid reason to contemplate a switch.