Heya,
The Cube is a great DAC and the AMP is rather decent. Anyone looking for a good source component that can grow, the Cube is it. Lots of options. Inputs from anything you can possibly imagine. Upscales. You can switch between devices too, so it's not a lot of unplugging and replugging, etc. I find amplifiers are not as important as simply having a great DAC for source and of course source audio being lossless. Anyhow, I still use my Little Dot MK III with my Cube simply because the Little Dot is a tube amp and I like to switch to it often. But the Cube can push my headphones, all of them, no problem. And it sounds great. It's just not tubey, which is why I have a separate tube amp for that. Otherwise, I have no need for a stand alone solid state amp when the Cube performs fine for that. I'm more interested in it as a DAC anyways, and it does that job beautifully. It can easily push 300ohm headphones.
The Mini and it are nearly the same thing if you look it over. The Mini is more expensive, comes with a remote and has a digital front plate that has a read out.
I happen to think the Cube look better too.
Very best,