I decided to give the center mount version of these G4 counterfeits a try.  I was pleasantly surprised with their looks but these are not the bees knees. 

Compared to R8000 brakes (tested on two bikes with similar setups, differing only by their brake calipers) the springs are firmer and require more grip strength but I imagine this would benefit frames with serpentine cable routing.  With Shimano pads, the braking is not quite as good but it's close.  Also unlike R8000, there is a little slop in the right side pivot, the side with the cable pinch bolt.  Somehow, this results in no squeal even with zero toe, but maybe this is more a result of the Shimano pads. 

I happen to have them set up with spacers for narrow, 22mm rims but I can confirm that they will accommodate rims up to 30mm by rearranging or removing the four 2mm spacers these come with. 

These will not fit on frames with dropped seat stays because of the amount of space required by the linkage and cable routing.  By my measurement, there needs to be at least 53mm of clearance between the brake mount and the seat tube.

There is one really weird thing about these brakes and that's the centering mechanism.  It's tool free, which is quite nice, but because of its design, only one arm spreads when opening the quick release.  This could be a problem with tires that balloon much wider than the rims.  See the second photo.

These weigh 101g for the front and 96g for the rear, without pads (that didn't arrive -- not the first time missing items from an Ali seller).  I paid $178.11 with tax and shipping to the US from a seller called F1Z BIKE SHOP, and they took 20 days to arrive.

If the real ee brakes are identical except for the badge and shoe fixing bolts, I have to assume that they have all the same characteristics.  Thus, other than the looks and weight savings, they're not better than R8000.