I've spent a few hours with it, and haven't touched the manual yet so there might be lots I've missed.
So far I only used it standalone, sampling from Nave and Attack.
Sampling is really nice and fast, in the plugin window you have a slider and a button on the left, set the threshold, press the button, play a key et voila, samples and assigned to a pad, now you can sitch pad or sample to a new layer.
Sampler is really deep and you double tap on any parameter to assign it to a modulator, which can be lfo, step sequencer, envelope, random or midi cc.
Sequencing is based on patterns, scenes and songs.
Patterns are, well pattern, Scenes are combinations of patterns and songs are linear sequences of patterns. Haven't spent too much time on them, but drawing patterns seems to be very fast, and you can open a piano roll for each pad.
Oddly enough, the first time I run BM3, Patterns for Nave and Attack only played monophonically, I only managed to turn them polyphonically by changing an option in the settings menu, might be user error.
Overall I can't help comparing this £20 app to my MPC Live and feel like the software side of the MPC Live feels a bit clunky in comparison, especially the effects.
Absolutely everything can be mapped to hardware so I guess you might be able to write a full mapping and use Maschine hardware to control this, that would be really interesting...