I like the Vox toneLab SE, and it's patented Technology, in which it makes it's 12AX7 tube be able to simulate other tube configurations, as well as provide dummy speaker loads for the 12AX7 to interact with. However, the bigest complaint fo that model was no Metal distortion tones built in to it.
I Myself, simply run My Metal Pedals, line selectable, after the ToneLab SE, and use them for My metal tone. And to not overpower My Metal Pedals, to get a muddy, or other undesireable over-clipped sound, I do not run an overly proccessed signal out of the ToneLab SE, when I need My Metal Pedals to be the obvious primary source of My Metal tone.
But I can use, more mild fuzz-tone, and mild distortion: pre-distortion tones, for use with My Metal Pedal setup. To run a preproccessed tone, even a mild fuzz tone, into a Metal Pedal, to get a two stage effect ( as they also actualy make two stage distortion pedals; with a fuzz or boost 1st stage, and Distortioon 2nd stage, as a standard pedal type already ) ----and what I do, is emulate these dual stage distortion pedals, by matching, and not overwhelming My pedal and pedal proccessor set up.