Heroism, Greater vs. Heroic Invocation

So, whenever I get someone capable of casting Heroism, Greater, along with Greater Enduring Spells and at least 6 level 6 spell slots, I keep Heroism, Greater on everyone in my party--that 4 extra attack and damage is quite nice, of course. But, it also buffs their skills. Once you get to CL 9, you get Heroic Invocation, which can give that same attack and damage boost to you're entire party with a single spell slot, plus some other stuff, but it DOESN'T buff their skills. So I'm curious as to how you guys deal with that. Is it worth it to keep a couple of Heroism, Greater spell slots and use those on people who have a lot of active skills? Or do you just think, I don't need Heroism, Greater at all anymore, just Heroic Invocation is fine? I mean really if your party is built well, then hopefully you've got at least 1 person who has a decent rank in every skill, right?