[AZLiberty]

Identical body, 12 fret vs 14 fret:

The difference will be in the location of the bridge. On the 12-fret the bridge will be moved lower on the lower bout. This usually results in a more fundamental tone (fewer harmonics) compared to what has become the standard location. Some folks will perceive this as having more bass, but its the lack of overtones that are the real difference.

Playability would be identical, except that the reach to the upper frets on the 12-fret instrument is about an inch shorter, so some folks would find it a touch more comfortable to play.

So in very general terms 12-fret is more fundamental, clearer sounding, 14-fret has more harmonics and is fuller sounding.