Finally the idea that any enemy that's Evil, including Rovagug, will pose a threat to any build that optimizes even a little bit for Smite, is laughable - the bonuses are simply too good. Ok he will land a bit of damage due to his stupid unresistable spell damage, he's still going down, fast.
Which is why I want to do the Paladin splash: bonus to saves via Charisma and Smite Evil.
If there's even a couple of evil enemies worth using smite on (Rovagug, Vordaki), then I think it's worth losing Superior Reflexs and a Magus Arcana (probably Ghost Blade).
Depends on priorities, I guess. Sure, Smite Evil is occasionally strong (but 1 use per rest kinda limits it to a handful of boss fights).
I think personally I'd prefer to prioritize getting Dimension Strike for boss fights. That would not delay other awesome SS class features (Lethal Stance, Bane Blade and others). Although I managed pretty well with neither Smite nor Dimension Strike (did use Arcane Accuracy though - and +9 AB for 1 AP is not bad at all; plus rod quickened True Strike with Vital Strikes).
Superior Reflexes does come very late, almost too late (it helps that I hit level 20 before Pitax Palace in Act 5). But it was as gamechanger for me, when I could stop worrying about rolling Initiative, getting flat-footed and relying only on Mirror Image/summons/running away not to be destroyed. Really changes how bold you can act in combat.
And Ghosts type enemies are among the most common and annoying in later acts.
I've found Ghost Touch very useful.
Well if you have a strong party less of an issue, as nuking (with Stormbolts and Mass Heal) is arguably the best way to dispose of them. Also less important if you do use ECBs and wield Clarity, I guess (though its not guaranteed).