Some folks swear by them.  My Dynaudio BM15s are wonderful, but do a bad job creating the sound of my car speakers or some ear buds.  
 
https://www.avantonepro.com/Avantone-Active-MixCube-Powered-Full-Range-Mini-Reference-Monitors.html
 
I went for black.  That cream is gosh awful.  

let us know how they sound,
and how it affects your mix decisions...

The ugliest twins you ever dated ... but you will eventually marry them and live happily ever after

They are good. I actually prefer one speaker to two with a mono mix summed into a single speaker.  It is still a better way to listen mono.  The other thing is turn them right down low.  The idea is not to have them up loud.  At low volumes all sorts of issues will stick out much more so.  Snares, vocals etc, the list goes on.
 
Spend time just getting everything sounding well balanced in the cube at a soft volume.  And then crank up the mix loud on your mains and revel in an awesome mix.
 
You still need to monitor up loud though on your mains for bass/kick sub energy and reverb levels though.  The small speaker down low will make you crank the reverbs up a little too high because you won't hear the reverb very well. And if you are it is way too loud!

My ol pal swore by them.  It took me ages to come around to buying them.  
 
I know what they are supposed to do. My Dynaudio BM15s are just so sweet, but they do not translate well for the car or earbuds.  
 
They are due in Thursday.  This weekend will see some heavy rotation on them!

I have one of them (black) in the center of my set up for listening to mono playback of a mix in progress. Really useful! You'll be very glad you have them.

I too like them for mixing in mono first (single speaker).

The midrange without a crossover frequency reveals every mistake...
 

You'll love them.  They're so helpful in setting vocal levels.

Is the Avantone site down? Haven't been able to get to it all afternoon...