2.  They were designed to be used in groups of 4 to 6 cabinets to get the desired SPL at very low frequencies (below 45 Hz).   A lot of folks are running them as singles and trying to EQ the bottom end to get more low bass output.   This pushes the drivers past their safe operating range very quickly.   If you need a lot of very low bass, use more cabinets.

3.  When one driver quits working, the other driver will fail as well because they both fire into a common high pressure cavity.   The user needs to look on the drivers as a single more expensive driver.   You always need to use two, so buy two.

4. Air leaks will kill the driver.   The driver has a VERY loose suspension and requires that the small chamber behind it be absolutely air tight.   Care must be taken to get that chamber sealed and keep it sealed.   Before every show, check all the screws that keep the cover on  as they may work loose and cause a leak.

5. You must use a high pass filter set to 35 Hz and that has a slope of at least 24dB per octave to realize the real potential of the design.   Many people are using huge power on these cabinets day in and day out, but they are the ones who run steep high pass filters on them.