I've got this urge to own a tapping head, so I've started doing a little
reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary dramatically
depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That seems
insanely fast to me. Are you guys who do this really tapping holes in a
fraction of a second?

Seems like for small jobs the clamping and positioning requirements to do
that would take longer than tapping a couple holes by hand.