Pair.com has, as far as I can tell, an excellent reputation as a reliable host. But old versions of software make me wonder about security holes and other version related problems.

I've been a Pair.com customer for many years. It's been my experience that they lean slightly toward being conservative in what they install, but they do stay on top of security issues. There are less expensive places to go than Pair, but their stability and connectivity have been more than worth it for me. YMMV.