The French cop a bit of Brit style with Le Crunch - their intention being 'M' flavour.
Channel A can deliver some of the glassy clean tones you'd get from Marshalls, while channel B ups the raunch factor for a more cranked-stack vibe.
In front of an amp to our ears, though, the gainier sounds are overly brittle with a top-end fizz that needs sorting by keeping the treble knob really low. However, careful EQ and lower gain settings deliver usable crunch tones.
If you're just looking for a Marshall-in-a-box pedal for in front of your amp, there are more practical options, but its ability to undertake a range of tasks may make it worth your while, not least that these pedals can be gig savers - you may wish to use them as boost/overdrive/ distortion pedals in your chain, but that XLR output can send speaker-simulated amp-like sounds to FOH if your amp breaks down.