the spell pen thing hit home with me when I was on my priest and noticed that the shadow resist buff gave me a 24% reduction in shadow damage done to me. Then applying the same principle to frost damage I do to others, it's a no brainer since such a huge component of a frost dk's damage is frost. The loss of a measly amount of strength to negate the spell resistance is well worth it imo.
I'm still on the fence about hit though, I probably should cap it for pvp but i'm undecided. hate to lose all the extra str gems.