I play in a heavy band with a wall of amps and cabs, and have been wondering, especially for bass (I am tuned very low) if the inner geometry of the cab really affects the sound once you pass a certain volume. I play through a 1975 Acoustic 2x15 and two new Mesa 1x18s.
Once you're playing LOUD the things that matter most are speaker behaviour at high power (thermal and mechanical non-linearity) and port non-linearity (but sealed cabs are rarely the answer to avoid port issues!) The internal geometry matters very little.