You don't mention it, but credit where it's due: DTrace, with the creation of which you had a lot to do, can be used in quite the same way in kernels that have added the TCP provider. I think we all owe you a big thanks.
I didn't create DTrace, but I did create the DTrace TCP provider and many networking scripts. A nice list of them is here: http://dtracebook.com/index.php/Network_Lower_Level_Protocol... . My scripts focused on tracing events, workload characterization at different levels, and some timing: connection lifespans, and 1st byte latency. (At least in that location; I've got DTrace scripts scattered elsewhere too). The tcpdive scripts have focused so far on perturbation study: congestion, retransmissions, resets. Also useful!