I've had 11 Wizards, so can speak from experience as opposed clips.
4 different 100w MCIIs all with V tranny---great midrange, not as full spectrum as a Marshall, it's own thing for sure, but far from "hollow" in the mids. It's a great mix of all mid frequencies and the contour helps fine tune whether your hearing more low mids vs upper mids. Low end is ample and has a thwack to it, like a concrete hardness, no flub. Can be bright or dark and anything in between via the treble, presence, bright, contour, and mids knob.
It's own animal, but definitely some Marshall DNA. When boosted and depending on settings, also takes on a little Mesa Markish tone/feel to my ears. Takes boosts like they're part of the circuit and with the right one you can get some killer compression/grease for the heavy stuff. Articulation, clarity, crunch, punch is top notch. Of all the Wizards I've owned, the MCII has the most growl, snarl, whatever word you use to describe aggression. Chords just sound mean AF...very pissed.
MCII 50w---One I had was a tranny other than the V, not sure if it was C or what, but it was quite different than the 100w V MCIIs I've had. I actually didn't care for it near as much. It had a different gain structure (more vintage maybe) and the mids were shifted to a place I didn't really like as much. There was a problem with the line out on this amp and the seller was great in taking it back, so I can only assume something wasn't right with the tone as it just sounded off in addition to the line out not working.
2021 & 2016 MC25---VERY close to the 100W MCII tonewise and actually a tad better IMHO. The mids are in a slightly better place to my ears and it's my favorite WIzard amp tone, it just doesn't fuck you as hard because of the smaller power section. Despite it's size/wattage, it still punches and hits hard, just not like the 100w. Despite no contour knob, it still has tons of range in the standard eq knobs to find any sweet spot one could prefer...bright, cutting, dark, blah, blah, blah. I'm running one now with TAD redbase 6v6 through a 212/412/active sub setup and it's an absolute monster.
MTL---one I owned was 2016. It just had a very neutral midrange that I couldn't gel with. Tried speakers, cabs, guitars, pups, boosts, eqs, still had this hollowish/neutral midrange. Other than that killer, especially with the sat/depth knob for the added girth/gain/compression.
100w Hybrid V tranny--I thought this would be the perfect Wizard for me in that it might have had the mids of the MCII but the saturation of the MTL. It was close but still lacked a certain grind/attack in the mids that the MCII achieves. Still a great amp and close to the MCII, but voicing, gain structure were still more MTL than MCII to me.
KT150 MCI MKII---CLose to the 100w E34L MCII, but had a bigger rounder low end with less of the sharp attack. I tried it with the stock KT88, 6550, KT90 and it always had that slightly rounder low end without the thwack/attack the 100w MCII has. Very very nice eq response though and the mids, highs, and lows just filled the space really well. Needless to say could really fuck hard and shake the walls.
KT66 50w W800---This may have been the most unique voicing/feel of all the Wizards I've owned. Think it may have been the C tranny. It was very open and didn't compress near as much as the others, even when boosted. It had a great eq response, killer mids, similar to Marshal but not Marshall mids. Low end was ample and tight but even when boosted with a modern pedal playing thrashy stuff, still had a slightly vintage feel/tone...hard to describe. All the others have had a more modern vibe where as the W800 reminded me a tad of playing late 70s era JMP or something. Not that same sound, but the attck and overall feel reminded me of that era Marshall.