If you're running a not so combat heavy campaign, being a stickler for material components is 100% fine by me. But, for my tastes, calling out the party mage's player for not keeping track of how many ounces of bat guanno he has & in what belt pouch is a bit excessive.
I do however, think that in the case of "epic spells", spells with costly components, or a spell that is a main plot hook for a adventure or campaign.
And I've recently started using "power components" such as vile/exaulted components, like a demons heart, angels tears, etc- items that effect the spells DC, or caster level. When you have a PC that carries a jar with the heart of a Vrock in it, he's badass... he deserves that +1 CL to cast a spell with the evil descriptor!