I went a slightly different route. My switches are linked with 10Gbps SFP+ across the apartment, but it was way too late (and too much hassle) to pull proper in-wall fiber. Instead I used one of those ultra-thin (around 0.1mm), unshielded fiber cables, and just snaked it through door frames and taped it along the walls. I'm genuinely impressed this stuff exists, it makes retrofitting fiber into a finished space so much less painful.

Most of my edge devices are still on 2.5GbE though, and I'm increasingly aware that for anything with plain SATA disks, the drives are the real bottleneck. Once I LAG'd 2×2.5GbE to get a 5Gbps pipe, it became obvious the network wasn't the slow part anymore in a lot of cases.

And yeah, the 10GbE SFP+ modules run hot, so hot that I would not lay my fingers on them for more than 2 seconds. I stuck 2 copper heatsinks on my module, not sure they do much but the module runs smoothly. Even so, I'm pretty happy with the overall setup: from my 10GbE-equipped Mac I can saturate multiple machines at once and I no longer think about the network most of the time, which was the goal.