It's very hard to write a review for an unbranded commodity item sold by more than one Amazon trader, because there is no telling whether they all the same product. Mine came from The AV Seller, so I can comment only on their product.
The positives:
The price was excellent.
Our broadband router tethered at the end of the extension managed to connect at 19+ Mbits/sec on a 20 Mbit line, so there were no signal quality issues that I could spot.
So, why only 3 stars?
The negatives:
The cable is the thinnest phone cable I have ever come across, which is a problem with such a long run.
If it had been a 3 metre cable carried in a laptop bag, the reduced bulk and weight would be great. But how many of us need to carry around 10 metres of modem cable on the road? Something this length will almost certainly be used for running a static extension from the phone socket, and for that purpose, the cable is far too thin. When fixed to the wall using ordinary phone cable clips, there is so much empty space between the cable and the clips that it is easily pulled out.The slightest yank would break it. And if you happen to hit it even gently with the hammer, forget about the cable.
In summary, if you are going to run it through a conduit, it's likely to be ok. Running it along a skirting board, or anywhere exposed, though, is not a good idea.