When I'm playing a low-int race, I'm the sort who will spend 3 practices to get certain skills to 75%. When I do that, I'm thinking "Ok, do I *really* need metal armor use? I mean, it's a nice skill, and it might one day save me if a rager's about to deathblow me and that one time metal armor use kicks in and the blow doesn't land..."

Usually the armor use skills are ones I'll practice with any "left over" pracs I have when I hit hero. Especially if I've already practiced legendary awareness and prosperous reputation (if applicable).