Tweak: Allow Greater Spell Penetration’s caster level bonus to apply to all caster level checks (not just to penetrate SR), including ones made for dispel magic or similar. This doesn’t apply to Spell Penetration, so you just get a +2 on such checks.
This tweak can really make choosing feats for your spellcaster more interesting. One problem with Spell Penetration is that it can feel very much like a “feat tax”–above a certain level, monsters with SR are so common that everyone has to take it, but it’s not particularly gripping, especially since the Greater version is the same old story.
This tweak adds some a little bit of extra utility to the feat tree, especially in those encounters where there aren’t any monsters with SR.
Many thanks to my friend David Finzi, who sparked this idea.