80 PLUS is the last thing I look for. There are way more important characteristics, that actually affect system stability, but 80 PLUS Efficiency isn't one of them.
The first thing to look for is a sufficient +12 Volt continuous current rating.
Second is very stable voltage regulation.
Third is very good DC output quality (i.e. good voltage spike suppression, very low noise and ripple).
Fourth modular connectors.
Fifth efficiency.