The Minilogue is awesome. Haven't used it live yet, still finding my way around it, so it hasn't had it's big test.
For me it replaces the R3, that I've owned for about three years now, but the minilogue could replace something like the microkorg too. The worst thing about those kind of synths is the fact that if you want to change anything to your sound live, you have to get intro the menu, try to find the parameter you want to change, and then you could alter it. The minilogue has a lot of buttons that are always waiting to be fiddled with. I love the fact that you have presets, but you can just start with nothing and later save that. It's a great machine, especially for 700 euros. Couple of drawbacks though: no sustain pedal input, and little keys, but both are apparently easily solved by playing it through a midi keyboard.
Oh and I love the fact that you can actually see the waveform as you modulate it.