Well, I haven't done much with it, and much of what I did was primitive. It worked well enough for the Agent Orange cover I posted. I got sidetracked with edits on that track, so I'm jumping back into things with a new idea for the Black. I need to explore the whole project/bank/song/pattern structure for longer compositions with multiple sections.
My impression so far is that aside from it being large, it is a strong asset. For me, the workflow makes intuitive sense. Enough menu diving and key combos to keep things powerful and flexible, but limited enough so that it feels performance oriented. The build quality feels great. I haven't come across any firmware bugs. I like having the CV for pitch/gate/mod and the ratchet and tie functions. It doesn't feel like it gets in the way.
I can't really say it is the best out there, since my experience with the field of products is limited, but it seems pretty strong. My biggest fail so far was trying to record a MIDI pattern into the sequencer. I'm not sure how or why I couldn't get it to work, but I'll try again.
The other sequencer that has my attention is the Frap Tools USTA. It seems to be good for getting weird. It is also big and higher priced.