The only real reason I need it is because I have many multi-way non-passive speakers (each driver in each speaker needs a discrete digital XO and amplifier channel), instead of a traditional analog XO board baked into the speaker.
The speaker's power-efficiency and SQ really increases greatly when the amp doesn't have to push through a bunch of resistors/inductors and caps before getting to the voicecoil. (I went from 1000watts to 10watts, that's a huge power-efficiency increase; and the SQ jumped like 5% which IMO is a big deal at this level.)
I also have a lot of subwoofers, 5 on the left, 5 on the right and 10 LFE subs. (i.e. Tri-channel bass.) With the Motu I can redirect any input to any output. So I could feed each subwoofer with just LFE or LR+LFE or just LR or any other channels. I could also redirect the LFE to the bass drivers in my mains and center without needing to engage any specific bass-management feature. All mixing and routing strategies are available all-the-time in real-time.
Obviously you can see how amazingly powerful that is. (It's also good for ABXing a large number of mono or stereo speakers at a GTG.)
I got tired of having to do live with mono-bass during 2-ch music. Now I get stereo-bass during music and tri-channel during movies, and it switches automatically. I don't have to use Y-Spliters or fart around changing settings and buttons in the menus.
It's really designed for pro-audio. Where you have a bunch of sources from a DAW that gets sent to a live concert system.
and where you have like 10 or more live mics recording the drums, guitars, and vocals etc etc and boosting them to the amplifiers.
You can mix and route like 64x64 channels with a click of the mouse; and apply basic EQ. It doesn't do the heavy bass management or Auto-EQ stuff found in HT-AV equipment, but with the PC version of Dirac I think you'd be there.
I chose REW and JRiver because it supports everything I desire, which is just manual EQ/XO's, that's all I need...
I wouldn't be surprised if hollywood uses them to feed an: analog to Dolby-Atmos encoder from a DAW.
The only downside, is that since there are no Atmos decoders for the PC (unless you pay Dolby $100k), one must still buy an AV processor and take an extra AD/DA hit. Where as the Trinnov is all-in-one and avoids that hit (but it is $40k!!!)
At 44.1 and Thunderbolt the Motu supports like 128in x 128out channels (if you buy enough boxes). At 192 it is limited to 16 in and 24 out if I understand correctly. At 96 you get 24x24 I think. Enough for a full atmos system.
If you found a Dolby Surround VST plugin for the PC, you could have as many phantom upmix channels as you desire, until high-channel-count Atmos boxes come out to replace it, then you just plug it into the Motu inputs and your done.
That way you don't need to buy 2 or 3 AVR's (unless you want to use them as external amps.)
A lot of musicians use Motu's: Gaga, Miley, Metallica, etc etc etc.