I have read controversial information and reviews regarding volca units. I'd already owned the fm2 (instant love), so I bought the drum as a second volca to experiment with. I mostly use it as a standalone drum machine with acoustic instruments, it sounds nice plugged into a jbl, perfect for "on the go" techno sessions. I also use it in my live sessions. There's a ton of tweaking options, I really like the concept of 6 identically shapeable sounds, althought it takes indeed a lot of menu diving to modify parameters during a performance. If you own a controller that can send midi cc, it can be a solution. I have read a review complaining about the separate midi channels per sound, stating that it's difficult to control, but the unit can be switched to work on a single midi channel, and this way it acts just like any traditional drum machine.
Overall it's a lot of sound design for the money it costs, don't let the term "digital" fool you:)