I agree with dagosto that putting the kick mic inside the drum is not the best recipe. For one you lose all of those low mid frequencies and harmonics, essentially the boom sound of the drum itself. Maybe for some types of music this would be desired, but with some keen compression you can keep that boom under control. If you place the mic inside, especially close to the beater, it's all punch/attack and no decay.
Think of the Bonham's drums in Zeppelin's version of "When the Levee Breaks". The kit breathes, has room to let the frequencies move to the mic/the ear. You hear the kit and the drummer. You hear the drum and not just the beater. I mean sure we are all using overheads, but for the most part you are capturing cymbals and snare. Even if you boost the lows in the OH's, the snare loses its top. Maybe we don't all want that "Levee" sound but its a good allegory.
I stole this from wikipedia:
http://en.wikipedia.org/wiki/When_the_Levee_Breaks
"The famous drum performance was actually recorded by Andy Johns by placing Bonham and a new drumkit at the bottom of a stairwell at Headley Grange, and recording it using two Beyerdynamic M160 microphones at the top, giving the distinctive resonant but slightly muffled sound."
I like to think about recording drums in two ways, first is that each drum is an individual instrument (which requires its own mic) and second that the kit itself is an instrument. Johns used two dynamics and the natural reverberation of a stairwell, he's not even using a kick mic...
What do you think?