I say, stick a nice delay pedal in the FX loop, and use the Output volume control as your master. This gives me a wider usable range of volume. I also wouldn't waste your time trying to get a distorted tone out of the amplifier section unless you're playing this at a club. Set the channel masters at 9oclock or so, and the Output volume is then comfortable to use. The gain/distortion in the preamp of the MkV is delicious, and totally 3 dimensional.
This said, I play LPs, with an SD Distortion and JB pups in the bridge, with SD Jazz pups in the neck. Though it's a fairly boring setup, I use the Edge mode in Ch2, and love the tone I get. It borders on sweet, clear, glassy single coil tones. However, the strings still feel soft, slinky, and chewy.
Anyway, use the preamp to your advantage, use the treble knob to give you some added gain above 12oclock as well.
Edit: FWIW, 16 Ohm cabs never seemed to play well with this amp, for me. I think the amp likes high current situations, including 4 Ohms, though my current 2x12 comes out to something like 7.5 Ohms in resistance (V30 and Creamback in parallel).