Re: Silly question about kick drum depth
For all other factors the same (diameter, wood type, shell type, edges, heads, room, mic'ed, unmic'ed...etc)........
IMO The 14 depth has more punch, definition, less resonance, shorter decay. None of those are bad things. They help give the bass a 'note' in a mix even if they don't stand out immediately to your ears or win in the loudness game
Greater depths have more resonance, longer decay, so the note lasts longer, is fuller, and the boom lasts longer, but there is loss of definition. Nothing wrong with that either.
I don't own 29 kick drums but having experimented with quite a few, my personal preference is the 14 depth.
IMO a 14 x 20 is great on recordings. Some pretty monstrous sounding drummers used a 14 x 20 (Phil Collins for one).