kinda meh imo, though if someone would give me all the volca's for free I wouldn't be mad ;-).
there's something about having something physical and interacting with it. computers are limitless and therefore full of distractions.
i don't actually use hardware that much personally, i've tried, but have rarely been convinced. i do like the idea of this box as a kind of sub-basskick box you can get hands on with... i think that's part of the appeal, the physical, tactile interface of hardware. For instance, when i started using USB controllers for the first time, the style of the music changed. it's definitely the kind of thing i would consider buying to play with for a while at least!