Thanks to Mark for the kind and well-written review!!!
Turbocharger increases the low-turbulent air-moving capability by doubling the port length--and hence maintaining full port cross-sectional area--instead of reducing the port cross-sectional area in half in order to obtain the lower extended bass tuning mode. I'm not sure why anyone would care to characterize it as "ugly", it is just a small box sitting on top of a much much larger box. The bent ports of the turbocharger really can't even be seen from the listening position. Also, it takes mere seconds to remove the turbo when not in use.
Most of the time, when using a single VTF-3 Mk3 without MBM-12, it would be best to run the subwoofer in max output mode for widest dynamic range and maximum output capability. Only on material with very deep bass (pipe organ music and some movies) would it be beneficial to use turbocharger.
Note that an MBM-12 will work really well with a VTF-3 Mk3 (with or without turbo). The MBM will take system performance to a much higher level.
Sincerely,