The dual cab block is a 50/50 blend, so you can get even more flexibility using 2 actual cabinets and use an A/B split to change the blend to your taste. I tend to use an SM57 up tight on a 1 x 12 cab and a 121 Ribbon on a 4 x 12. I usually end up with a 30/70 blend preferring the bigger, thicker sound from the Royer and mixing in the 57 to get the exact amount of attack and percussiveness I am looking for. I don't know what the DSP hit between the dual cab vs 2 actual cabs is, but it is one more beautifully flexible feature I love with my Helix!