I bought it for live use with Ableton and Traktor. The unit is very slim and lightweight so it fits perfectly in my laptop bag, while still being really sturdy and good build quality. It works with Ableton straight away, and takes very little time to learn. I haven't used the mk1 version, so it's all new to me. Mapping it to Traktor is a bit more challenging, as Akai hasn't published specific midi implementation charts which would help e.g. with assigning different LED colors, but for the most part it seems very easy to setup to any software.
I'm really looking forward to actually taking it to gigs and I'm sure it will perform really well.
Deciding between this and the Push is simply a matter of needs - if you need something to actually make music with, buy the Push. If you need a controller for performing, this seems to be the best at the moment.