Well, I got the paints last Friday and after a short rest after GLAM, I immediately tried them on a few miniatures.
I thought about posting some WIP shots of the paint jobs but quickly discarded the idea because these photos would actually prove nothing except for showing just another paint job!
But first:
I have several racks designed for Vallejo paints and the Reaper paint pots have identical measurements, so they fit in nicely:

Then I thought about what would interest me if somebody would tell my about the qualities of a new range of paints. One of the essential points would be their opacity in conjunction with the grain of pigment. So I started priming a tile in black and painting it with small samples of the paints I had available. When I was half finished, I realised that a test on a white surface would be equally important, so I primed a part of the tile white and did the same all over again, d'uh.
The left sample of each paint was done with the paint applied straight from the bottle after shaking it thoroughly, while the right one was mixed with an (about) equal amount of water(Or thinner as I use a 1:6 mixture of water/Future Floor Wax for diluting my paints...).
Here goes:

The pic was made in daylight without using flash. I adjusted the levels until I got a result on my screen that seemed quite accurate. Mind you, I did this on a macbook, not on a 'proper' desktop display.
As you can see, the coverage is quite good, even diluted they seemed to be easy to control when it comes to transparency!
What I liked about the paints was that they dry with a matt finish, this should make them very attractive for those painters who prefer not to varnish their miniatures. I can only concur to Orctrader's remarks about intermixabillity with other brands, I tried EE, Vallejo(GC and MC, inks and washes), Duncan Acrylics and Lukas Acryl-Paint. All went well.
One thing I REALLY might like about them is as Orctrader has mentioned before: They have a different nozzle than the Vallejo paints. I already have heard from other painters that these paints do not clog up. Only time will tell, though.
It might be a personal thing but knowing that there is a small skull in your paint pots in order to stir them while shaking is a really cool thing! And it would be a cool rumour, too! Well, a rumour it is not:

It would have been nice to test the metallics as these always are a big 'if' concerning acrylic paints, but these were not included in the lot.
All in all, I really can recommend them. Since a few weeks, I considered buying the complete set of Rackham paints in a bargain. Not anymore! I will use these paints quite frequently in the future.