The knees of the bees
Before buying this synth I heard that the learning curve was pretty steep, and while that is somewhat true, there are plenty of online resources to help you get your bearings in the Elektron orientation. The first night sitting down with this I was able to compose some incredibly clean and powerful sequences, and with the performance functions, tweak-ability is basically unlimited. A deceptively powerful sound engine, unbelievably vast sequencing capability and pretty much all you need to make some killer sound in one compact, sturdy build of a box. I highly recommend this instrument to anyone who works with electronic music. The only limitation is the four voice maximum for polyphony. Even still there are sneaky ways to make the very most of this and you can, of course, bring in other components. While there are synths that offer more or equal polyphony, I just don't think any of them accomplish what the Analog Four does for what it is and how much it costs.