I used to support a company that refused to run fibre, and had just run ethernet everywhere with the old 10GBE modules. Half their links were constantly flapping as the hardware powered off to cool down.

Even with the new modules, their ethernet cable runs were always in excess of what 10GBE could handle. I remember one at ~140 meters that was constantly renegotiating.

The worst part is, they had not a single element in their network that didnt support fibre. The fibre sfp modules for their radios was the same cost as the copper.

I love that these 10GBE modules exist but please (please please) just run fibre if you can.

10Gbase-T is here to stay because you can deliver POE over it to wifi APs.