I use a 5" offset hole around the 4 o'clock position. That position just allows for a better 'fit' for my mic stand. The following 4 points come from Prof. Sound's Drum Tuning Bible.
1. Any hole larger than 7" is like having no head at all on the drum.
2. A 7" hole creates the feel of a one-headed kick drum, feeds more beater attack direct to an audience and provides some of the tone of the resonant head. Further, it's easy to position a mic and change internal muffling devices, if used.
3. A 4-1/2" or 5" hole, or even 2 such holes, offset, allows some relief for rebound control of the kick beater, contains more of the drums resonance so that the resonant head is more pronounced in the tuning of the drum. A 4-1/2" hole is difficult to get large mic's positioned within (but can be done) and/or internal muffling altered.
4. No hole, very resonant, creates more bounce or rebound from the kick beater. It can become difficult to get the "slap" of the beater and resonance of the drum both when miced with one microphone. The muffling remains inside. The resonant head is very predominant in the overall sound.