You really do need to take manufacturers' specs with a large pinch of salt. They exaggerate a lot. A figure for sensitivity is meaningless unless you know how it has been calculated. Ideally, that means a frequency response curve measured under standard conditions – the kind of thing pro speaker system manufacturers provide.
Anybody can make a bass cab that has high sensitivity in the midrange, but unless the LF can keep up, it will sound unbalanced. Anything between 94dB and 97dB is a reasonable figure for a medium sized 12" cab. 99dB is almost certainly not an honest figure.
Doesn't the MB have a larger cabinet? If so, it might be marginally more sensitive at low frequencies (where it counts) than the Aguilar, but not much.