Hello from England where I have been enraptured by most of Boogie's products for nearly 30 years and have owned and loved a lot of their output ever since and am now a badge,tie and blazer wearing member of the Mark Five club.
The one constant companion throughout this seemingly endless journey has been the old style Boogie Thiele 1x12 cabinet loaded with an EV12L.This gives an immense bottom end and as your previous correspondent rightly says it's best place is on the floor.
I have placed Marks 1,111 AND 1V Combos atop this ( I don't think the Mark 11c ever made it across the pond !) every time with splendid results because you always had the perfect marriage of low-end grunt from the sealed cabinet and the sweet zingy highs from the half - back of the combos, which incidentally were always loaded with the Black Shadow EVs.
Now some may argue that having two EVs in tandem like this would provoke an overly clinical, almost too clean tonality.
However I always found that with the incredible amount of headroom on offer in this combination, if you spent time wedding the tone and volume controls of the guitar to the particular nuances of the amplifier (sadly an endangered species of guitar culture) then a whole world of sonic possibilities was there to be explored if you could think in terms of the amplifier and attendant cabinetry as being instruments of their own right in themselves.
I now have a Mark Five head, two open back 1x12s and a pair of antique 1x12 Thieles
all loaded with very old EVs and the results are superb.
It's a virtual 4x12 at a quarter of the weight, it's a vertical 2x12, it's a horizontal 2x12 and gosh golly it's both at the same time ! How much more versatility can you want ?
A wholehearted endorsement of the good old Thiele 1x12.