Wow, love it.
Now I really wanna track down the Sunn 1x18 with the CV 18 to match my 1200s. Sunn and Accoustic were actually doing very similar things with cab design in the 70s as well as being somewhat unique in insisting on higher end drive units.
But, before you crown the king of the big amps, you gotta try a Traynor Monobloc ;P