My experience with PIX code suggests keeping it current but not too current (unless there’s a new feature you have to have). So as a rule, I always stay on the latest revision of the previous version. For example, they’re on 6.0(1) now, so I’m running 5.3(2). When 6.1 comes out, I’ll move to 6.0(last) unless I find reason to move sooner (bugs, features, or security advisories).
