In today's times, there are so many of these "midi percussion multi pads" and "midi pads with samplers".  They are all good products for what they do, but in my opinion, nothing is more sophisticated and detail oriented than the DrumKat.  For one, there are no moving knobs, buttons, or sliders that could be easily broken when striking the instrument.  Second, the pad design is set up like as conventional drum set, and not just in square blocks like some others.  And third, the ability to completely tailor the feel, response, and after-touch of each pad is unparalleled. I also like the fact that the designer/builder is a player who really knows the needs and logistics of the player.