I`m running my Invader 100 through Marshall MF400. I bought the cab just to try those K100`s. I like it so far. The sound is fat and clear but you have to be careful with bass and depth knob. It takes my tubescreamer really well and you can get great tones both with and without it. The versatility is the key word here.
Channel 1 is meant to be a clean channel but you can get to hard rock/heavy metal territory with gain knob high and hi gain button engaged very easily.
Channel 2 supposed to be Marshall-esque but I like only the low gain sounds from here. Very JTM-ish if you ask me.
I`d like to try these two channels with some tele.
Channel 3 is my main rhythm channel. First I was quite disappointed with it due to its scooped character but with bass around 9 o`clock, mids at 3-4 o`clock, treble at noon and bright button engaged (depth 8 o`clock and presence depending on volume) I could get the sound I wanted.
Channel 4 is quite opposite to ch3 - it is very mid-heavy. This channel can sound flat if you want it to but with little tweaking you can find really a lot of very useful lead tones.
With bright button off the sound is kinda woody. With bright on it is more crispy. I like both.
Funny thing is that it seems that this amp does not like EMG 81 I have in my LTD M-400. It sounds great with Ch1 and Ch4 but I don`t like it with Ch3. It has tight low-end and clarity is really great but mids are somehow thin. It feels like they picked only a certain frequency, not the whole spectrum. I`m already thinking about to swap them for some passives. My chinese el cheapo sevenstring with some uknown OEM passive pickups sounds remarkably better - big, fat, clear and brutal. The only thing it`s missing is a bit of definition. Other than that I`m pretty happy with the results. Hopefully in near future I`ll lay my hands on some quality guitar. I can only guess how it will sound.
edit: this is my video or better a short clip with that LTD M-400. I don`t remember if it was boosted or not.
https://www.youtube.com/watch?v=JjVzdcCI7rg