After deliberating for a very long time, I ended up buying a Maschine and not an MPC. I thought the standalone nature of the MPC would be great for getting me out of the "engineering" mindset and into the "playing an instrument" mindset. The Maschine does that, because you can (and should) work with your computer screen turned off. It's not any less portable because (most) MPCs don't work on batteries and laptops are pretty easy to carry around these days. And it lets you perform the "MPC way" (finger drumming, sample chopping) as well as a more traditional way (play notes and chords on synths and edit them live). Playing on its pads like a melodic keyboard is very inspiring for me - there's no priviledged scale or distance like on keyboards, it's all by ear and feel and it helps me be a lot more creative with my melodies.

Anyone into electronic music should have one in my opinion.