However short duration tests are fantastic for testing short-duration power, like sprint power, track tt power, or pursuit power. Why go to WKO4 to calculate "PMax/FRC" to get sprint power when you can just go do some sprints!

Why bother with anything "modeled" at all when the real thing is so easy to test for these days with power meters on just about every bike and trainer? (at least in Slowtwitch land). Coggan himself says something like "the best test is the performance itself" (or something very similar to that) about 12x per day

I can see modelled FTP being useful because doing a "pure" FTP test regularly sucks for those who don't do pure FTP-test-like races. (FTP is super easy for me to track because I do lots of pure 40K time trials). Though I'm fast enough at 40K that you might claim it overestimates my FTP because it's too short. :)