One other thing that stood out to me is the licensing. Their disclaimer mentions that the demo injects some noise periodically in the mix. They will even let you download a fully functional version of the software as a demo for either the Mixbus4 or the Mixbus32C. The manual is the same for both versions. I downloaded the user manual, which is available here and appears very well laid out. They do provide support for Presonus Faderport8 and 16 as well as supporting Mackie MCU compatible controllers, like the Behringer XTouch. Using a mouse for mixing is pretty clunky. It would seem a natural for a multi-touch screen. I'm curious about how you control the faders. They have a section in the installation portion about CPU usage and the first topic is, " Why does Mixbus require more CPU usage than my other DAW?" They are pretty up front about it being a CPU hog. Minimum is a dual core, but I think the last single core PCs were in the P4 era, so that shouldn't be an issue. Recommended processor is 4+ cores, which means an i5 or i7. They may offer a plug-in to support MP3, but I didn't see any mention of one. If you're building tracks from the ground up, that isn't an issue, but if you use it for something like the VJR, you'll need other conversion software. The only thing I see is no built-in ability to import or export MP3 on the Windows and Linux versions.
It appears to work with anything that has an ASIO driver (Windows), CoreAudio driver (Mac OSX)and ALSA (Linux).
I spent some time this morning on the website.