Works very well. Amazing.

Without amp, the French network, I have a bar, not even 2G. Just enough to call with difficulty.
With the amp is between 2 and 4 bars + 3G, depending on weather conditions and operators. (SFR and Bouygues).
It was thus the problem without internet in addition to the very good voice.

And again, the receiving antenna is now installed under a Velux, 2nd floor, INSIDE.
When she is on the roof, the floor 3.5ème will be even better, I hope.

As for (small) negative points:
+ Internal antennas really do cover a large room. With a multi-story house or spread, so do not hesitate to take the system to 3 antennas.
+ Cables for indoor antennas are therefore a bit short.
+ Finally, it tends to cut a long conversation. Therefore, I hesitated to put only 4 stars, but as the system is far from being made according to the rules of art, it would be unjustified.

06/06/2015: I have (finally) installed the antenna on the roof.
Some bars and more. Works very well.
The cables are really too short. We must buy more -> 50 EUR quickly if ceut quality.