They are definitely my favourite bass amp.
I moved away from them a few years ago and went through loads of different heads and cabs from a variety of makes at modest and stupid price points but then came back and it felt like home. I've used them in big band jazz and in power trios.
99% of the time I just want a touch of compression, an MB head and cab and I'm happy. I find they take pedals well when I need a bit of grit.
MB heads work well with a variety of cabs but I'm not as convinced about MB cabs with other heads. That way round seems to miss something to my ears.
All the heads have the MB sound, some with some valve flavouring, and others with a different EQ set up with different number of bands and centre points of the bands.
Most of the time I leave them all at noon or reduce the bass a little to stop any booming if the room is a bit crap.
I am not that precious about "tone" - as long as I've got a good compressor then I'll plug into pretty much everything, but MB kit makes me smile.