I have already bought 3 of these and so far it seems decent for its cost. How long it will last in outdoor conditions compared to regular hoses remains to be seen. The spray gun is also of decent quality, generally does not leak, and on its own costs about half the price of the hose+gun package. I should note, however, that:

1) Do not be fooled by the 15-meter size. In reality, it is more realistic to calculate it at half the stated length. On a balcony 8-9 meters wide, the hose stretches quite a bit to reach from one end to the other, to the point where you start to worry about the tension developing on the quick connectors and the tap itself. Later, I cut it in half and used it on a balcony 3.5 meters wide, where I found that even 7.5 meters of hose was still stretching a lot and required effort to reach from end to end. Therefore, wherever you plan to place it, first do the 'divide by two' calculation to be sure. Do not expect to stretch it so much that you get the 1:1 ratio that non-spiral hoses have, so the '15 meters' is slightly misleading. It would be more accurate to say something like '15 meters that practically correspond to 7-8 meters of regular hose, just easier to store due to the spiral.'

2) If you happen to cut the hose into smaller sections, know that you will need 5/16" (or 8mm) quick connectors to connect both ends. The packaging may advertise it as 1/2" or 3/4", but that only refers to the connector with the tap. The hose itself is narrower and will not fit such a connector. It definitely requires 5/16".

UPDATE after 2 years: One of the spray guns was left outside during the winter, unused for months with the tap closed at the spout, but it seems it somehow got damaged internally, leaked from the sides, and was thrown away. One hose was slightly torn/cracked in one spot (possibly from sun exposure?) and sprays a jet of water. It can be patched but I don't see it lasting much longer. For the money, I still think it's a good system.