First - I'm not a drummer, but I wanted to get a sampler and something to try how drum kit feel, without taking much space. I use it for now with two pedals, and it's good for trying things out, learning and training in rhythms. It's UI is very intuitive - despite having a lot of buttons - 10 year old kid can handle simple operations well. It's a bit noisy in playing, but may be it's my lack of skill - I'm sure it won't be a big deal on set, but may cause an inconveniece with neighbours. Sometimes pads I played did not trigger or triggered other pads - I guess I can fix it with settings. Pad comes with latest firmware update, which is cool and ableton live lite license, which is useful. I still handn't tried it as a soundcard and a midi controller (no usb cable in box :( ). Build is solid, legs are not moving on table. I'm planning to get a stand to use with it later. It have a huge sample library - I hadn't went all over this meanwhile - but what I heard is of decent quality. Anyway, you can load your samples with USB disk on key.
You also need to get drum sticks in order to use it, they're not in kit.
Overall my impression is good, but it can be a bit better, if Alesis would include sticks or USB cable into package. Thomann(I guess?) put the right power adapter for my country, so I could use it out of the box, also it's cheapest price by far here, even including shipping and taxes, after checking amazon and local stores.