My use of a sound interface is a little different than typical audio engineering. I am an amateur radio operator and amateur musician.
The main focus in my choice of the 8A is for interfacing my PC to multiple radios and software defined radios for analog audio from 10-4000 Hz voice and AFSK digital modes to SDR IQ signals to the PC for panadapters and demodulating. I also use it for my single (purchased along with the 8A) Shure SM7B mic for the mic input of the various radios. Typically the audio is fed either to the PC via the PC speaker line in or via (also new AKG K712) headphones for both radio and music audio, but the 8A can take PC input on the Windows sound channel 1-2 as the PC output setting in order to listen to PC audio via the headphones or (depending on the digital communications application software) other direct channels for the AFSK digital modes.
The 8A's onboard web browser control interface is very nice! It allows me quick access to the inputs and outputs and with the range of filters and compressors available in the mixing as well as the auxiliary and group sends, each radio has its own or even multiple inputs on the mixer that allow different "pre-set" filter settings for the various modulation modes used for voice or data to cut high frequency noise or boost the low or mid-range voice. It also lets me split the mic into several inputs again with various filter/compression settings for the different voice modes from a wide FM range to single-sideband modes where I use a "ragchew" conversational flat (SM7B through) response and a "DX" (long distance contacts) setting with a low shelf and emphasis on the 1-2k range for added punch on the SSB signal.
I found that using the Thunderbolt interface is best (Windows 10 PC) as I had some glitches with USB 3 staying connected, although I believe that is a problem with my PC and not the 8A. I have many devices connected to USB and before adding the 8A one of the other USB 3 devices has had the same connection problem, that is my basis for the determination that the 8A is not at fault. Indeed I always intended to use Thunderbolt and the USB 3 use was only temporary while I acquired and installed the Thunderbolt 3 PCI card for my motherboard. The USB 3 cable was an important factor, I used two different brands as the cheaper of them just wouldn't get a 3.0 connection. And while the Thunderbolt connection will allow you to access the onboard software controls, that would sometimes get lost after long periods of being connected to the browser so I find that the ethernet LAN connection via my router is the best way to have "always on" web browser control.
The sound via Thunderbolt is outstanding and glitch free and I nominally run at 96k for the bandwidth of the IQ panadapter view and other SDR and so the audio. The 192k works well too but for the types of use right now I don't deem it worthwhile just for the benefit of the frequency span of the panadapter, 96k is a good balance between the digital and the audio needs.
With a buffer of 256 samples on the 8A and Ableton Live 9, Live 9 reports a latency of 3.33 ms each way for a total of 6.67 ms.
Having described how well the 8A works for an amateur radio operator, from the perspective of music audio at least as coming from the PC as CD or internet music audio or the output of my Ableton Live 9 "productions" (I use quotes because I am a novice at that) into the headphones, the sound is fantastic.
With no real intentions to use the 8A for music when I was purchasing it the fact that I also purchased my first MIDI controller/keyboard at the same time for use with the Ableton Live software, is certainly leaning me toward at least the use of the Shure mic via the 8A for the musical work that I am learning to do. The work was initially geared toward helping my wife produce Pre-K through 1st Grade audio teaching tools/clips for her teaching job but Im sure it won't stop there!
So why the "WOW! Blown Away" rating? I have had (for amateur radio use as described above) a M-Audio Delta44 and a Focusrite Sapphire PRO 14. Typical PC sound cards don't have enough I/O for a serious ham. The Delta44 was a nice start to find that music audio sound interfaces are great for amateur radio. The Focusrite which is just one year old now, raised the bar with the ability to do some routing and mixing but I quickly outgrew the number of I/O. The MOTU 8A seriously raises the bar up high with many versatile I/O with performance and controls that make it an outstanding sound interface for my use.
Hopefully I was not too wordy and the review describes all of the important points. I'm afraid that the actual music audio production/engineering that you may be looking for is not covered in this review but I hope that this review of the 8A as a sound interface is useful to both musicians and amateur radio operators.