My Mic Pro has arrived, and all I can say is - wow.  BUT - I'm actually not at home for a few days, and so I am only able to test it with items that are to hand - not my best headphones, and no access to analysis tools on my PC (although it may be possible to do that remotely...).  Still, I know the sound of those headphones well, and the playback really was impressive.

Note that I bought only the mic, not the wireless receiver.

First, it is somehow smaller than I expected.  Given that its buttons, mics, and LEDs are around the edge, there is only just enough room for them. It comes with a soft carrying bag with space for accessories. As an extra, I bought the full size wind muff which wraps round all three mics. 

Setting it up was very straightforward using the app, which includes a remote record button and a slew of optional settings (which I have yet to explore).  So within a few minutes I was testing it out by speaking a nursery rhyme into it (as one does).

But then came the challenge of how to hear the result.  I don't have a PC here to connect it to.  It has no playback ability at all.  The only way to hear the recording is to access the file via the USB-C port, which they also manage to cram into the periphery.  Luckily I had brought from home one of those thingys which plugs into my phone and which has a number of USB sockets on it, and connecting that to my phone and to the Mic Pro enabled easy access to the file on the device, which I then copied onto the phone.  The phone saw the Mic Pro like an SSD or the like.  Then I unplugged everything, plugged my headphones into the phone via a USB adapter, and replayed the file.  The phone seemed perfectly happy playing a 32 bit float stereo file.

Frankly I wasn't too impressed.  The stereo image was slightly odd and the sound of my voice was indifferent - but then again, most of us don't like the sound of our own voice!  However what probably didn't help was that I had the mic in my hand, which could well have been occluding the mics a bit.
 
So then I tried recording the replay of a short track featuring a young lady singing with a jazz band. And this time I put the mic on the table in front of the speakers (again, not the world's best speakers, just small bookshelf ones).  When I replayed that, my jaw dropped, as the frequency response was great at the top and bottom ends, and the stereo image was spot on. It simply sounded like what I'd just been listening to.  At the end of the track I detected no audible noise, and I'd had the music playing pretty loud.

At the point I had to attend to domestic matters, but of course I will be doing further tests as the evening progresses, and reporting back here.  But my initial feeling is that this is a device to be taken seriously.  OK, the lack of monitoring and easy playback might rule it out for some, but the plus points, coupled with the USA price of just $99, seems to me to make it worth considering by anyone wanting to record 32 bit float stereo with a device that is barely there at all.  And all you do is press one button.  OK, two if you count the power button as well. 

And despite hours of reading reviews and watching the slew of them on YouTube, I seem to be the first person to spot its potential as a tool for field / location recording etc.  I think Insta360 may not realise what they have created.

I will also be considering mounting options. Just holding it in your hand can be problematic as it's hard not to end up with your fingers on,  or too close to, the mics.  But it can be clipped to something like a bent piece of cardboard held in the hand with the mics unobstructed.  Or clipped to a baseball cap so long as you don't move your head.  Many possiblities.

Oooo, I'm going to have fun with this...

Same era/type of devices mate, thought I would weigh my input....   

The Tascam is a 4-track recorder, so the SD card has twice as much data to process.

Since nobody asked, I haven't had problems with SD cards on any of my recorders.

...and wondering why anyone (or any two?) would post about their SD card performance for their R-05's when the question was for the DR-2D. 

Same era/type of devices mate, thought I would weigh my input....   

^ I may be wrong, but I think most reports of 4060s distorting is due to their high sensitivity. A lot of recorders couldn't handle the signal.

I run 4060s on stage for rock shows and almost never face distortion issues. Only if I set them directly on top of the sub and in the lowest freqs I can eq out. 24v phantom power via Tascam FR-AV2.