I had forgotten only the Ergomo displayed TSS. So I suppose what I do with regard to TSS during a workout is conditioned by the fact that I can see realtime what my TSS is for the workout.
In the future, I would like to start to plan weeks based on TSS goals, and even plan my builds and peak. But, given it's only my second year of racing, and given that I'm already halfway through my first build and on the way to a May peak, that will have to wait until later this season or next.
From what I've read, some people have had considerable success using the Perfomance Manager to plan a season. It definately strikes me as something that could become more widespread in the cycling community at some point. At the moment, though, it seems to me that others (and myself) are using the TSS model to a degree, but not to its full potential.
It's interesting, then, to hear from people who do utilize to a greater degree, with considerable success.