I enjoy their write-ups on optimizations they have made to the TCP/IP stack in the Linux kernel. Why? Some of the testing they have done I can replicate on my own hobby systems. I don't use all of their tweaks but I did learn a few things in the process and sometimes their changes can be useful to me for reasons unrelated to what they were trying to accomplish. For example, I did not know that the kernel devs added a "-3" and "-2" option for net.ipv4.tcp_adv_win_scale and I found that setting it to 1/8 buffer mem for my DNS servers reduced the kernel memory usage when my servers were being abused without having to globally lower the total buffer memory allocated.